Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Cambered Tires Can Improve Fuel Economy

timothy posted more than 4 years ago | from the my-heart-has-four-cambers dept.

Transportation 317

thecarchik writes with an excerpt from Green Car Reports: "We already know that it's possible to curb your fuel consumption just by having your tires properly inflated, or better yet, installing a set of low rolling-resistance tires, however, soon there may be an additional avenue to look at when picking the most fuel efficient rubber for your ride. The answer is the camber of your tires, more specifically, the negative camber. This is when the tops of your car's tires are angled inwards towards the chassis. Of course, there are negative effects too — namely increased tire wear and impaired ride quality — which is why production cars almost always have zero camber." The linked article, as well as the New York Times article from which it draws, describe a new tire which is designed to minimize those negative effects.

Sorry! There are no comments related to the filter you selected.

"Negative Effects" (2, Insightful)

JakiChan (141719) | more than 4 years ago | (#33260354)

If you ask me it IMPROVES ride quality. Some of us don't like driving a car that feels like an overstuffed sofa on wheels.

Re:"Negative Effects" (5, Informative)

JazzyJ (1995) | more than 4 years ago | (#33260378)

Perhaps you should get your shocks replaced....

Re:"Negative Effects" (1)

Ethanol-fueled (1125189) | more than 4 years ago | (#33260388)

Obligatory Rice Boy Page. []

Re:"Negative Effects" (-1, Troll)

Anonymous Coward | more than 4 years ago | (#33260544)

Unless your fat. But apparently being fat decreases fuel efficiency, so that should be outlawed or taxed soon. But fat people basically have told me that they want to drive a big soft couch while watching tv, eating potato chips and talking on their cellphones.

Re:"Negative Effects" (4, Insightful)

aoteoroa (596031) | more than 4 years ago | (#33260650)

I wonder if the increased fuel efficiency is simply the result of creating a smaller contact patch for the tires and reducing the rolling resistance. Maybe the same result could be acheived by using skinnier tires...but they wouldn't look as cool.

Re:"Negative Effects" (4, Insightful)

Lt.Hawkins (17467) | more than 4 years ago | (#33260988)

if thats so... I don't want one (or four?). I want larger contact patches for better stopping. Screw 1 MPG, I don't want to hit that kid / dog / train that ran out in front of me.

Re:"Negative Effects" (1)

no-body (127863) | more than 4 years ago | (#33260998)

Yeah, like this: []

Throwing out your existing tires for fuel economy? How much oil is in those tires anyway?

Add 2 PSI to regular tire pressure and your roll resistance goes down. Another great factor is driving style and type of car.

Bigger topic..

How? (5, Insightful)

Sarten-X (1102295) | more than 4 years ago | (#33260360)

How does this help fuel economy? More to the point, how is this story anything but an advertisement for some guy's new tire?

Re:How? (5, Informative)

DevConcepts (1194347) | more than 4 years ago | (#33260390)

In a pure theory aspect, less tire on the road, less rolling resistance.

Re:How? (1, Insightful)

Anonymous Coward | more than 4 years ago | (#33260882)

The real question is, "Is the money saved on fuel more than the amount you will increase spending on tires?" Don't cambered tires wear faster? ...not to mention a higher chance of punctures being irreparable, and thus necessitating early tire replacement?

Re:How? (0)

Anonymous Coward | more than 4 years ago | (#33260996)

Even if it isn't, the lessened emissions would make it a preferable choice for some. Not everything is about minimizing the $ amount. Although rubber waste isn't exactly good for the environment.

Re:How? (1, Informative)

Anonymous Coward | more than 4 years ago | (#33261076)

In a pure theory aspect, less tire on the road, less rolling resistance.

Is that general theory or specific to tires? Doesn't most of the rolling resistance from a tire come from deforming the tire? So then wouldn't any camber just load one side of the tire more heavily than the other, so there would be more deformation on that side of the tire? This would only be beneficial if there were some net reduction in rolling resistance.

From TFA the patent is for a new tire with an asymmetrical side wall height where the outside would be higher than the inside. Based on the diagram there is still the same amount of tire in contact with the road, so it seems it is not just a matter of putting less tire on the road.

Re:How? (5, Insightful)

Lotana (842533) | more than 4 years ago | (#33261084)

In a pure theory aspect, less tire on the road, less rolling resistance.

Now I am completely new to this whole area, so please don't flame me too hard if what I ask is something stupid and obvious.

It is logical that less friction, less power is needed to keep the wheel spinning. But in poor, wet or icy conditions I need every unit of friction possible for safety (Aside: What is the unit of measure for friction?). Therefore, isn't this new tire design makes it more difficult for me to brake and thus more hazardous?

Saving me money in fuel is good, but if some child runs out in front of my car on local road and I can't stop in time with these tires...

Re:How? (1, Interesting)

thesupraman (179040) | more than 4 years ago | (#33260406)

I suspect this is pure stupidity along the lines of the contact area, hence friction would be lower.

Of course just using a narrower tire does the same thing, but since everyone wants to see
nice wide tires under their cars....

On a poorly designed suspension setup you could get more grip in corners thana narrower tire
like this, but that is in effect a design fault.

And ihave a strong doubt there is anything they can do to mitigate the wear problems except
make tires with thicker tread on one side, which is double stupid - wear will still be higher. I
suspect the additional costs would be higher for the tires than any saving.

The fact is, if you care, just run narrower and harder tires.. Thus giving lower friction and
more economy, duh!

Re:How? (3, Insightful)

LurkerXXX (667952) | more than 4 years ago | (#33260444)

On a poorly designed suspension setup you could get more grip in corners thana narrower tire
like this, but that is in effect a design fault.

Just about every sports or race cars out there ( including Formula 1) have negative camber. You are saying that is a design default? Righhhhhht.

Re:How? (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#33260470)

I second that.

"thesupraman" is a brain damaged retard. Cut off his testicles to stop him from making more copies of himself. Fuck.

Re:How? (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#33260516)

Why the profanity? Cunt.

Re:How? (1)

sheddd (592499) | more than 4 years ago | (#33260488)

If I may be so bold as to guess what the grandparent meant:

"If the car doesn't have a touch of camber in turns (whether thru camber, caster or other adjustment) then it's got a shittily designed or tuned suspension and this stupid tire might make it work better."

Re:How? (5, Informative)

thesupraman (179040) | more than 4 years ago | (#33260506)

Sigh, go and learn something you retard.

They dont, any competent and not class limited suspension design dynamically adjusts camers in corners to develop the desired cornering camber, while not causing issues in strange line.

A lot of moronic 'boy racers' like to think a ton of negative camber is the sign of a race car, mainly because some suspensions designs develop a lot of un-adjustable negative camber when cars are over-lowerd.. This of course is terrible for handling (but they like to think it is not.) but since those cars cannot have it adjusted out with spending real money....

And F1 most certainly does NOT run static negative camber, it would be a disaster for straight-line handling. They run DYANMIC camber in corners due to the uneven A arm suspension geometries.

I suggest you start here.

Re:How? (-1, Troll)

PinkyGigglebrain (730753) | more than 4 years ago | (#33260740)

Think you could actually cite something we can read on line? Both the link you give are for book that you have to buy.

And you insult someone who was trying to answer a question, so what if he was wrong? Calling him a retard only shows how limited your vocabulary is.

Great way to back up your statements and boost your credibility.

Now I suspect your going to try and make some biting remark about me and anyone else who calls you on this.

Funny thing is, either way I win. If you don't understand that, well, perhaps you need to work on subtly.

Ummm, sometimes the answer is in a book (3, Insightful)

Sycraft-fu (314770) | more than 4 years ago | (#33260784)

Sorry if that goes against the short attention span mentality we generally have these days, but that's life. Sometimes there isn't a good or reliable reference for something online, you have to go get a book.

"either way I win"

No not really. You may "win" in your own mind but that is meaningless. If you mean "win" as in convince others you are right, you have failed. Sorry.

Re:Ummm, sometimes the answer is in a book (1)

kaizokuace (1082079) | more than 4 years ago | (#33260846)

well, back to the arguement. From what I've seen, in non dynamically adjusted suspensions, during cornering the lateral load on the wheels is a lot and causes the wheels' camber to change mid corner. Adding a little negative camber helps the outside wheel achieve zero camber under cornering loads achieving more grip in corners whilst giving up some straight line traction.

Re:Ummm, sometimes the answer is in a book (0)

Anonymous Coward | more than 4 years ago | (#33260980)

Is it about "winning" the argument, or about allowing the truth to stand?

It's OK to be wrong. But if you know that you're right, you better be able offer something to support that fact with a little more weight than a link to Amazon.

(Why? Because over here in the reality presented upon us by forums such as Slashdot: In the best case, by the time Amazon ships the book and we read it, the discussion is likely to be archived anyway, and nobody reading this thread in the future will ever know if your assertions have been peer-verified or not.)

Re:Ummm, sometimes the answer is in a book (1)

PinkyGigglebrain (730753) | more than 4 years ago | (#33261058)

You missed it too. I don't care what everyone else thinks about my post, in fact I expect it to get modded "Troll". Think for a moment about to whom any victory matters, it is always the self. If you think that a victory only counts if you get a parade then I think you need to spend more time meditating on it.

As to the book citations. If thesuperman wanted to back up his claim that LurkerXXX was wrong then he should have done more than say "read these you retard".

As it was I found a couple of articles that actually seemed to back up LurkerXXX about negative camber, I linked them in a follow up comment on the original posting so if your interested have a look. Another factor is that thesuperman seems to make the assumption that LurkerXXX was talking about static camber. Which was never explicitly mentioned by LurkerXXX when he states that race cars have negative camber. They use dynamic suspension with variable camber sometime plus, sometimes, like in turns, negative. At least that was my understanding of the articles I looked at. I don't really care about racing, I think there are much more entertaining things to do than watch a bunch of cars drive around in a circle for hours, but to each their own.

Re:How? (1, Troll)

PinkyGigglebrain (730753) | more than 4 years ago | (#33260778)

Wow, a few seconds on google and I found something that contradicts your statement about camber.

The amounts of camber gain varies from car to car, team to team and even by the engineer’s philosophy on suspension set-up.


Pushing the bodywork down (such as when the wings develop down-force) compresses the suspension, and if the car has a camber gain curve, the camber angle will increase. This change in camber may be desirable during high speed cornering

Found this here [] .

Since your such the expert perhaps you would care to summarize the article for us?

Re:How? (1)

PinkyGigglebrain (730753) | more than 4 years ago | (#33260802)

Sorry, I missed the part in your posting about "static" camber, something the OP never mentioned. In that regard you are correct. Perhaps next time you should try taking a less aggressive tone and more people will understand what your saying rather than being distracted by thoughts of you being various parts of a horse.

Re:How? (0)

Anonymous Coward | more than 4 years ago | (#33260894)

You need to work on your apologies. Perhaps next time you should try not to take offence at every little thing and engage your brain to try and comprehend what someone else has written, that way you'll understand what others are saying, rather than being distracted by your own vitriol? You went to the trouble of quoting an article, which aside from the out-of-context quotes in your post, shores up the argument of the GP. Stop. Think. Post. In that order.

Re:How? (1)

mr_stinky_britches (926212) | more than 4 years ago | (#33260822)

"Boy racer"-isms coming from "thesupraman". Awesome.

Hard to bash Supra's with stuff like this, though:
The Texas Mile [] .

Re:How? (4, Insightful)

Sycraft-fu (314770) | more than 4 years ago | (#33260828)

Also I wish that people would stop looking at how race cars do things and assume that it is good. Race cars are specialized machines designed for a specific purpose. They are good at what they do, but that doesn't mean they are good at everything.

For example you would find that many kinds of race cars would have real trouble handling on normal roads. They rely on the downforce generated by their high speeds and the heat changing the properties of their tires. On regular surface streets and speeds, they don't perform so well.

Likewise you wouldn't want a racing engine. Not only could you not use it but those things aren't built for longevity. The cars badly tear themselves up over the course of a race. The engines are pushed to extremes. However they needn't survive for more than a single race, another one can be had next time around. Wouldn't be so nice on a regular car though (even though it would last longer due to being used less intensely).

If you want to drive a car on the street then, well, you want a street car. It turns out the engineers behind them are usually fairly savvy and the design decisions are made for a reason. This includes things like the camber of the wheels.

If you are going to race a car, great, then you probably do want to modify it and there are some cool classes of racing purely on modified street cars. However realize that it is expensive, and generally you have to do a good deal of mods for it to be worthwhile. Don't just lower your car and think that matters to any real degree. While lowering the suspension is likely to be something done in converting a car for racing, that doesn't mean that lowering it alone is going to get you anything driving around town, other than some scrapes from speed bumps.

And really, if what you want is more performance in a street car, you just need to spend more and buy a more performance street car. Go get an Audi S4 or something. It'll have more power and speed than you can use on any street outside of the autobahn.

Re:How? (1)

Anonymous Coward | more than 4 years ago | (#33260870)

This is actually wrong. Many modern racing groups have penalties for using replacement engines, for example blowing your engine between qualification and race time will result in forfeiture of position (IE go all the way back to position 3x or so.) Additionally many racing groups now require the same engine to be used for the season with penalties for repairs/replacement. I don't remember exactly what groups do this, but I'm pretty sure Formula 3 and some other racing leagues do.

Point is: Engine reliability has reached a point where longevity *IS* expected, even from racing engines (Exception being Top Fuel type drag racing, where you're usually rebuilding between heats.)

Re:How? (4, Informative)

LurkerXXX (667952) | more than 4 years ago | (#33260930)

Also I wish that people would stop looking at how race cars do things and assume that it is good.

No one said a negative camber is good in all circumstances just because most sports cars use it. Heck, on Indy cars, they often have positive camber on one side of the car because they always turn one direction. Even among racers, they adjust the amount of camber by what type of course they are going to be racing on. In many cases for every day personal cars, 0 or close to 0 camber is the best setting, for others a slight negative camber is going to work best. The point was not that every car should use negative camber. It's that saying "negative camber is a a design defect" is moronic.

Re:How? (5, Insightful)

JWSmythe (446288) | more than 4 years ago | (#33260824)

    Race cars are made to turn quickly. Street cars are made to drive on relatively straight roads. There's a huge difference in the setup of the vehicle.

    Oval track cars give negative camber to the right side, and 0 camber on the left. That's because they always turn left. They even adjust their brake systems to assist in this (more braking power on the left side). As the car turns left, the body rolls to the right, shifting the weight to the right, and increasing the surface area on the right contacting the track.

    Street track cars (like Formula 1) expect to turn both left and right, so they get negative camber on both sides. Regardless of the direction they turn, the body rolls (much less, but it still does), and the weight is transferred to the outside of the turn. As that happens, the negative camber comes closer to 0. At a stop, sure it looks odd. In practice, it's what keeps them on the track.

    If you set up a race car like a street car (0 camber), you would see a race car that fails to perform as well as its peers.

    If you set up a street car like a race car, you'll be able to corner a lot better, but you'll reduce your braking ability in straight line stops, and your tires will wear significantly faster.

    With the negative camber tires, as the body rolls, they'll suffer the same fate. Instead of riding on the largest part of the tire (the tread), they'll roll up onto the outer edge.

    We won't see these tires showing up on production cars any time soon. If they are even produced, they'll be a sad fad like the Aquatred tires. The original version (circa 1991) They increased resistance to hydroplaning, but reduced overall traction due to less surface area contacting the road. The better innovation was improved groove patterns to reduce hydroplaning while still maintaining a large contact area. The Aquatred II and Aquatred III kept the brand name (and hype), but operate like a normal tire with good tread patterns.

    If this does make it to market, I'd shelve it right along with the fuel line magnets that align the atoms of the gasoline (or whatever); the electric supercharger that is only a marine bilge fan; and my all time favorite the battery cover insert for your cell phone that will increase your signal by 1000%.

    I'd never compare it to a tinfoil hat though, those really work. Aliens, nor the government, have ever read my thoughts from space. :)

Re:How? (1)

AK Marc (707885) | more than 4 years ago | (#33260968)

As the car turns left, the body rolls to the right, shifting the weight to the right, and increasing the surface area on the right contacting the track.

Weight shift is a result of the turn, not the body roll. A car with no body roll would still have weight shift in a corner.

Re:How? (0)

Anonymous Coward | more than 4 years ago | (#33261052)

Look at the front wheels of a NASCAR vehicle. The right wheel will have lots of negative camber, and the left wheel will have a visible amount of positive camber. This is for left-turn-only tracks, of course.

Re:How? (2, Funny)

Ihmhi (1206036) | more than 4 years ago | (#33260606)

The fact is, if you care, just run narrower and harder tires.. Thus giving lower friction and
more economy, duh!

Ah, so that's why my mountain bike uses so little gas. Makes sense!

Re:How? (1)

aoteoroa (596031) | more than 4 years ago | (#33260686)

The fact is, if you care, just run narrower and harder tires.. Thus giving lower friction and more economy, duh!

Ah, so that's why my mountain bike uses so little gas. Makes sense!

That's a pretty good analogy. Mountain bike tires are optimized for traction. Take a look at the bikes used for tour de france which are optimized for speed and reduced rolling resistance.

Re:How? (1, Informative)

Anonymous Coward | more than 4 years ago | (#33260528)

Not just camber my little friend.
Caster, scrub radius, toe. Reverse every manufacturer recommended settings and you'll be well on your way to giving big multi-nationals the finger.

Seriously, this is total BULLSHIT. From some shilling journalism idiot.
Camber is set to give optimal contact for your tyres. Which results in optimal handling, braking, safety, reliability.
If you want minimal tyre contact, you are looking for a bicycle, not a car.

If it works... (0)

Anonymous Coward | more than 4 years ago | (#33260370)

Good for them. Have the government set up a rebate to have many, many people switch tires if it really does increase fuel economy without other negative effects.

If we ever do switch over to fully electric cars we can go back to the current tires.

The best part of this is that it's re-thinking the wheel!

Re:If it works... (1)

sznupi (719324) | more than 4 years ago | (#33260460)

W8, assuming this new tire (or any other tech that improves efficiency) is indeed better, why would we "go back" after a switch to electric cars?

Re:If it works... (1)

eugene ts wong (231154) | more than 4 years ago | (#33260888)

Thanks for asking. I thought that it was just me. I had to reread it, to confirm that I really read it right the first time.

BMWs, Minis (3, Interesting)

Raleel (30913) | more than 4 years ago | (#33260372)

Apparently, BMWs and Minis (and probably other sport-ish cars) are negative cambered because it helps with handling. I found this out replacing the tires on my mini... the ones that I burned through in 1.5 years because I drive it like a sport-ish car ;)

Re:BMWs, Minis (1)

Dragoniz3r (992309) | more than 4 years ago | (#33260442)

I don't know anything about minis in particular, so maybe this question is stupid/redundant, but why didn't you rotate your tires to even the wear out?

Re:BMWs, Minis (1)

oldhack (1037484) | more than 4 years ago | (#33260568)

They tell you to rotate radial tires front-to-back on the same side. Also, with directional tires, you can't rotate from one side to another.

Re:BMWs, Minis (1)

JWSmythe (446288) | more than 4 years ago | (#33260860)

    You shouldn't rotate radials from side to side, without remounting them. The direction of rotation must be maintained.

    Directions, well, it's obvious, and marked on the side of the tire. :)

    You *CAN* rotate between sides, you just have to be sure the tires are remounted so they're still rotating in the same direction. A crayon or white grease pencil is good for keeping track of this.

    I haven't driven a mini, but my girlfriend has one. I'll check out the tires tomorrow. On most cars, you won't find extreme wear on either side unless there's an alignment problem. By the time a side wears too much, all of the tread has worn too much.

    I have a problem on my car where both sides of the front tires wear a lot, but that's from hard cornering. The tires stick fine, so why slow down too much for a turn. Driving roads like Angeles Crest Highway [] would always cause noticeable wear after just one trip. It is a beautiful drive up to the Mt. Wilson Observatory though. Well, it was. I don't know what the recent fires did to it.

Re:BMWs, Minis (3, Informative)

SydShamino (547793) | more than 4 years ago | (#33260622)

I have a BMW, not a mini, but my car's tires (645ci) are completely different front-to-back, plus the tires are designed for single-direction turning only (i.e. grip works one way, not the other). Put those together and my car's tires can't rotate. They stay where installed until they wear out, which the rear tires already have done once in less than a year.

Then again, there's these really nice, sharp corners on the freeway that I can take at posted speed (though never higher, of course) when most people slow down to 45... $350 tires (each) is part of what I bought when I picked the car.

My rear tires have a static negative camber. I have no idea if it helps the abysmal fuel economy or not, nor does it really matter. I offset the carbon in other ways and I don't care about the cost.

Re:BMWs, Minis (1)

SydShamino (547793) | more than 4 years ago | (#33260638)

The tire grip also differs from inside to out to handle corners, so I can't rotate the tires side-to-side by putting the inner surfaces out, either.

1. No rotate front to back.
2. No rotate side to side by flipping the direction the tires turn.
3. No rotate side to side by setting the tires inside-out.

Re:BMWs, Minis (1)

mindbooger (650932) | more than 4 years ago | (#33260810)

The extra negative camber in the rears is just to make the car understeer at the limit, which keeps the "general population" from losing the rear and suing the mfgr. It gives the minority something to undo to really make it enjoyable to drive. :)

Re:BMWs, Minis (0)

Anonymous Coward | more than 4 years ago | (#33260634)

If the tires are directional (direction of rotation must be consistent), the same side will be out no matter what position they are on the car. You can more the front drivers side to the rear passengers, but the same edge is still out. And if there is a considerable amount of negative camber, then it'll always wear the inner edge. For instance: If he's got significant negative camber and he does nothing but highway miles. In that instance the solution is to corner harder and faster, and more often, this allows for a more even wear pattern :)

Re:BMWs, Minis (1)

Aranykai (1053846) | more than 4 years ago | (#33260816)

It wouldn't address camber wear because the inside of the tire is still the inside. Unless you remount them on the wheel, the same part of the tire is in contact with the road.

Re:BMWs, Minis (2, Informative)

Anonymous Coward | more than 4 years ago | (#33260558)

Not uncommon. I have an older volvo wagon (245) Many owners have modified the stock arrangement to allow for a small increase in negative camber. Most people end up with -.5 to -1.5 degrees after some grinding and or drilling (nothing drastic). Upshot? A pretty much universal agreement that it improves cornering DRASTICALLY, and improves tire wear also. That's right most people report a noticble *improvement* in tire wear. (my car is stock and wears the tires unevenly FWIW) There are alot of variables at work here, suspension systems move, tires flex and the sort. People here are making the assumption that it increases tire wear, it doesn't always. In the case of an older volvo it's win-win, with perhaps the only negative being a small reduction in straight line handling, but not one that's very noticable.

Exaggerated? (5, Insightful)

grantek (979387) | more than 4 years ago | (#33260386)

TFA is light on details, and I fail to see how anything other than zero camber can be optimal for straight-line travel. I can see how it could reduce rolling resistance during cornering (in the same way it improves grip), but if you're looking to improve braking as the article claims, I'd be looking at caster (angling the wheel forward like the front wheel of a "chopped" motorbike) before camber.

Re:Exaggerated? (1)

Jeff DeMaagd (2015) | more than 4 years ago | (#33260532)

I'm not seeing how this improves fuel efficiency unless you're always turning. Unless you live on a winding road, it's hard to see how someone is on a tight enough curve for this to change efficiency on typical roads.

A lot of cars seem to have enough caster built into their suspensions, I don't know how increasing that will change efficiency. Another thing to consider is that changing caster probably won't require special tires, and this guy is out to sell special tires. I would guess that it's more an astroturf on a green blog than an actual product that helps fuel economy.

Re:Exaggerated? (1, Flamebait)

Joce640k (829181) | more than 4 years ago | (#33260924)

SImple: Less tire area in contact with the road = less friction. Adding camber reduces that contact area.

The guy in the article claims to have invented a tire which doesn't wear out so fast when you put camber in your suspension. That's what this is all about (reading comprehension!)

contact patch. (1)

dadelbunts (1727498) | more than 4 years ago | (#33260398)

camber wont help anything if the tires have the same contact patch. negative camber + regular tires = smaller contact patch so you get better fuel economy as less tire actually touches the ground.

Well DUH! (3, Insightful)

BLKMGK (34057) | more than 4 years ago | (#33260400)

Gee, less contact patch equals less friction and rolling resistance - and less traction with more treadwear on a narrower part of the tire if you get stupid about it. The car may also feel darty in a straight line but caster can also cause this. Auto manufacturers set alignments for more than just ride comfort and I'm pretty sure zero is NOT how many are set. Sheesh!

I know, lets put bicycle tires on cars and bump pressure to 120PSI. Bet it will get great MPG! Never mind the side effects...

Re:Well DUH! (1)

BLKMGK (34057) | more than 4 years ago | (#33260422)

That said - a cambered tires sounds interesting. Just not sure how having a cambered tire compensated for by an adjustment in camber on the suspension is going to do anything a properly adjusted suspension couldn't already do. WTF?

Re:Well DUH! (1)

Mashiki (184564) | more than 4 years ago | (#33260702)

Funny story. I was doing my apprentice ship for a mechanic split between two shops, one day a guy rolls in with a spare and a fully blown out tire. I mean so blown out that various parts of the sidewall were missing, and the tread section was partially torn from the tire.

Well that was fine, we sometimes see catastrophic failures of tires due to mechanical defects which is what this looked like. But in this case no. Checking the other 3 tires on the car, they'd been inflated to 110psi. Fun stuff, I'm surprised he didn't blow 2-3 more on the way over. Needless to say, they didn't honor his warranty.

Re:Well DUH! (1)

drsquare (530038) | more than 4 years ago | (#33261034)

Since when does lower contact area with the same weight mean less friction? That wasn't what I learnt at school.

A little help (5, Funny)

gmhowell (26755) | more than 4 years ago | (#33260404)

I don't really understand TFA. Could someone post a car analogy for me?

When it is a car thing.. (5, Funny)

Junta (36770) | more than 4 years ago | (#33260474)

It has to be a computer analogy. This is kinda like when you are uploading files, but need them to go faster. You do that by leaning the computer back so the bits flow out of the back of it faster. Same deal here.

Re:When it is a car thing.. (1)

bobdotorg (598873) | more than 4 years ago | (#33260576)

Whoa - hold on there cowboy. That's only if you're uploading heavy bits.

Re:When it is a car thing.. (0)

Anonymous Coward | more than 4 years ago | (#33260670)

Don't you know anything!? The weight of something doesn't effect its falling speed!

Re:When it is a car thing.. (1)

NotQuiteReal (608241) | more than 4 years ago | (#33260920)

That's only if you're uploading heavy bits.

No heavy bits. (unless you like that sort of thing.)

What most slashdotters really want to know is how to optimize the motion of the naughty bits.

Re:When it is a car thing.. (0)

Anonymous Coward | more than 4 years ago | (#33260656)

It has to be a computer analogy. This is kinda like when you are uploading files, but need them to go faster. You do that by leaning the computer back so the bits flow out of the back of it faster. Same deal here.

Also changing the oil in your hard drive will improve bit rate flow.

Re:When it is a car thing.. (1)

Tokerat (150341) | more than 4 years ago | (#33260856)

It's more like putting all the swap space on the outer disc tracks and installing the drive vertically so the arm moves in a downward motion when seeking towards swap - it makes paging in/out just a wee bit faster in situations because the drive arm gets there faster due to gravity assist.

...which is likely complete bullshit, but so are most of the car analogies I've read :-)

Re:A little help (0)

Anonymous Coward | more than 4 years ago | (#33260482)

I don't really understand TFA. Could someone post a car analogy for me?

It's like moving in stereo. Your car's mpg will shake it up. The experience will let the good times roll. Just like my best friend's girl.

Re:A little help (1)

Aranykai (1053846) | more than 4 years ago | (#33260832)

Yeah, but who's gonna drive you home when your tires explode?

Re:A little help (0)

Anonymous Coward | more than 4 years ago | (#33260534)

Imagine a car. If you turn it on its side and leave the fuel cap off, then fuel will drain out and that implies lower fuel consumption for the car. Now imagine the wheel is that car and you can see what is going on here.

Re:A little help (1)

muphin (842524) | more than 4 years ago | (#33260600)

think of a boat, the more is it connected to the water the slower it is (more friction/drag),

you reduce the surface resistance on the wheels you reduce the drag, placing the tyres at an angle reduces this drag while maintaining speed.
now one might think the more surface contact the more grip, therefore the faster you will be, the more contact =more resistance, which in turn uses more power.

So many other links (2, Interesting)

countertrolling (1585477) | more than 4 years ago | (#33260430)

Why do you people keep pushing one that requires registration?? Here, Watch some Leno []

Is it really going to work? (1)

Gazoogleheimer (1466831) | more than 4 years ago | (#33260438)

This stuff has been messed with before, and we've stayed where we are for several reasons...

...also, the lower your rolling resistance, -it used to be- the lower your traction was--although supposedly they've fixed that some too.

Also, has anyone considered how spookily this will change steering response?

(I wonder why it seems like we're willing to exchange fuel economy for safety and aesthetics lately to such a degree. Huh.)

No fuel efficiency bonus (4, Informative)

Sierran (155611) | more than 4 years ago | (#33260440)

The summary and the article it was taken from are misleading and poorly written. They only use the term 'fuel efficiency' to describe one possible effect of mucking around with your tires in general, probably by increasing their pressure or using harder tires. However, the CamberTire appears to have nothing to do with tire rigidity - and hence fuel economy - whatsoever. What the article appears to describe is a tire which is optimized by shape for negative camber, in order to improve handling of the vehicle, without the faster tire wear that putting negative camber on regular symmetrical tires produces.

WIth negative camber, the tire will be able to withstand more lateral force since it is angled out at the bottom, 'into' the turns. Thus it will be able to corner harder without losing grip.

Re:No fuel efficiency bonus (1)

sheddd (592499) | more than 4 years ago | (#33260514)

The only reason I see that this tire could theoretically grip more than a conventional tire is that for a given width of tire the contact patch will be larger on an asymmetrical tire. Just get wider rims/tires if you need more grip, narrower if you want more economy.

Re:No fuel efficiency bonus (1)

adolf (21054) | more than 4 years ago | (#33260578)

Lots of cars have negative camber.

My old E36 BMW 325i, for instance, has a fair bit of negative camber specified for the front and the back.

Having driven the car for six years, I feel qualified to state that the tires seem to wear very evenly, even when using the non-directional, mount-any-way-you-like, so-soft-it's-almost-funny Blizzaks that I use in the winter.

They seem to last a good long time, too, compared to other cars that I've driven that have zero camber.


Re:No fuel efficiency bonus (1)

jrumney (197329) | more than 4 years ago | (#33260616)

Normally negative tire camber would increase the fuel efficiency for the same reason it increases tire wear - reduced contact area with the road in a straight line in order to have maximum contact area when cornering. However, this setup changes the shape of the tire in a way that will negate both the fuel efficiency and the increased grip when cornering (as the cornering forces will push the tire up onto its side, the same as if you were running normal tires with neutral camber).

Re:No fuel efficiency bonus (1)

TomXP411 (860000) | more than 4 years ago | (#33260688)

The core problem with this idea is that the tire is essentially a cone. So when the tire is rolling in a straight line, the outside edge will be turning faster than the inside edge. This will produce more tire wear and more rolling resistance than a cylindrical tire, sort of defeating the purpose.

The best way to improve handling would be to design a suspension system that introduces camber when the vehicle rolls into a turn, but does not introduce extra camber when the vehicle is carrying additional weight. GM attacked this problem 20 years ago with their automatic ride system: the car is equipped with air shocks and a compressor that automatically levels out the rear end when you put a load in the trunk (or the back seat).

I bet they work even better... (1)

John Hasler (414242) | more than 4 years ago | (#33260492)

...when inflated with nitrogen.

Re:I bet they work even better... (0)

Anonymous Coward | more than 4 years ago | (#33260548)

...when inflated with nitrogen.

I had someone try to sell me on that scam once (of course they have to as part of the job). I just said to him "Sir, I have a degree in Chemical Engineering." and he stopped right there and got on to the business I was actually there for.

Re:I bet they work even better... (1)

DigiShaman (671371) | more than 4 years ago | (#33260666)

It's only a scam if your using it for the wrong application. The primary purpose of nitrogen is that the bottle source contains no moisture (humidity).

In an SUV, extra moisture in the tires wont matter much. But in a Corvette or BMW with low profile tires, it can matter a lot! The smallest amount of moisture in the tire can cause it to go from under-inflated to over-inflated and back again. Such a dramatic change will cause abnormal wear depending on how hot it's outside and how long you've been driving.

Re:I bet they work even better... (4, Funny)

tsalmark (1265778) | more than 4 years ago | (#33260834)

Sir, I do believe you've been sold.

Re:I bet they work even better... (0)

Anonymous Coward | more than 4 years ago | (#33260852)

I've got this ocean front property in Arizona ... The real reason to use nitrogen is that it comes in a tank, instead of bringing a compressor. For *aircraft* tires and tires that run *extremely* hot, you care about the oxygen in the mix oxidizing the inside of the tire. For racing, where you're looking at half a PSI as a big deal, it has a minor, predictable affect. For anything you drive off an dry, swept track, you can't tell the difference, and if you think you can, you're such a lying shit bag that you've sold yourself on your lies. I've got some oxygen free monster cables for you.

Re:I bet they work even better... (0)

Anonymous Coward | more than 4 years ago | (#33260884)

Nitrogen in tyres has nothing to do with moisture and everything to do with leakage , AIR seeps out the tyre quicker than Nitrogen , I know this cause the poster about it was on the wall at the tyre place when i was there last week getting new low profile , inward cambered tyres on my mazda sports car that apparently defy's manufacturer norms !

Re:I bet they work even better... (1)

DigiShaman (671371) | more than 4 years ago | (#33261116)

In high humid climates (Houston, TX), it's about keeping the moisture out. Most air compressors at the shop don't filter it all out. Their air tools can handle some of it, but the removal of moisture is for the air tool's long-term protection. It's even worse after a rainy day. You don't have to use nitrogen, but it's more convenient as a source of moisture free gas.

Now if you live in an arid climate or parts of California, you could easily get away with regular compressed air (atmospheric). It's already dry enough.

Re:I bet they work even better... (2, Funny)

ushere (1015833) | more than 4 years ago | (#33260672)

better yet, helium....

Re:I bet they work even better... (2, Funny)

aiht (1017790) | more than 4 years ago | (#33260992)

Hydrogen for me! Driving in my car's a blast.

Well, duh... (0, Redundant)

epp_b (944299) | more than 4 years ago | (#33260540)

Less rubber on the road, less friction, more fuel economy. How is this news?

Re:Well, duh... (1)

RatherBeAnonymous (1812866) | more than 4 years ago | (#33260808)

I have not made a specific study of car tires. But, rolling friction is a function of deformation of the wheel and the surface it's rolling on. Basically, due to tire and road deformation, a car is constantly driving uphill. Contact area is not specifically relevant. Because it spreads the car's weight out more, a wider tire would, in theory, deform less and deform the road surface less and reduce rolling friction. However, a wider tire would weigh more, increasing rotational inertia. The car would need more gas to get moving. Once up to speed, a wider tire should help gas mileage, unless the wider cross-section increases wind resistance too much.

What about toe-in/toe-out? (0)

Anonymous Coward | more than 4 years ago | (#33260546)

I'm sure excessive camber can affect fuel economy to some degree as it increases the grip each tire has and that does create some rolling resistance.

But a much greater impact would come from excessive toe-in/toe-out. (The tires are always slightly turned in toward themselves or away from themselves). Too much toe and each tire is essentially trying to drag the car in opposite directions and this creates much more resistance than camber. It wears your tires out very quickly, too.

Camber changes as the suspension compresses. (1, Insightful)

Anonymous Coward | more than 4 years ago | (#33260552)

It's called dynamic camber. A car with 0 static camber at rest will gain some camber as it's suspension compresses because it pivots more or less around an axis. Those of us that do competitive driving will generally dial in static negative camber so that in a hard turn, the tire doing the work is near zero camber, and therefore has it's largest possible contact patch. Of course we drive around skating on the edge of our tires in a straight line, but that's OK, it just wears out the tires. Under acceleration weight shifts to the back of the car, compressing the rear, and getting you to zero while you need it (Assuming that you have a rear drive vehicle). Similarly, when you brake, weight shifts to the front of the car, bringing the camber on the front tires, and setting them us to work best when they are stopping the car. The fronts always do the majority of braking because of weight transfer.

So anyway, this guy as come up with a way to get a tire that is skinning when you need it (straight line friction reduction), and wide when you need it for cornering, acceleration and braking. It's conical rather than cylindrical. It's hard to say if the tire actually holds together for long straight trips, but I think the idea is sound and rather clever. I'm interested to see how the car would feel in transition. Grip would always start rather light and build as weight transfer brought more of the tire to bear.

Skinny tires (1)

future assassin (639396) | more than 4 years ago | (#33260580)

Wouldn't they do the same thing. Decrease friction = better gas mileage?

But who cares I love my unpractical 35" Pro Comp Xtremes and my 16 mpg truck which I drive 100km to and from work 6 days per week.

Re:Skinny tires (1)

noitalever (150546) | more than 4 years ago | (#33260866)

Yes... exactly. It makes no sense to go to a wider tire and then tip it up to one side so only part of the tread fully touches the pavement while going straight. Unless, you were more concerned with looks than actual performance,and you buy into what the salesman tells you WHICH is most of the younger ricers, soccer moms, and wanna-be playboys in their cars where they offset the performance of their cold air intake and exhaust with huge 20" wheels that weigh 4 times what the originals did and wide tires that drag more.

so... if you're trully concerned with gas mileage, get some really light skinny wheels and skinny tires.

But, since manufacturers have realized that they can spread a bit of misinformation, we get the following 1. Sell someone wider wheels and tires 2. listen to complaints that the customers gas mileage is bad now. 3. Realize and spread the info that negative camber helps gas mileage. 4. Oh, it kills your tires? then now we have special tires that compensate. 5. Sell them the new tires 6. And... the Brooklyn Bridge is for sale if you buy five of them now.

Repeat with cell phones that last less time than the contract, and retire!

Re:Skinny tires (0, Troll)

Joce640k (829181) | more than 4 years ago | (#33260942)


(But you also lose braking/cornering ability...not that American car designers seem overly-concerned with that - I think they only put big tires on American cars because consumers prefer them).

More expensive tires that need replacing often (2, Insightful)

networkzombie (921324) | more than 4 years ago | (#33260726)

Just what I need; tires that wear quicker. I couldn't give two shits about my mileage. Where are the inexpensive tires that don't deflate? Isn't there a honey-combed tire that I can afford, or will it put firestone-death-wheels out of business? Yeah, yeah, I know. They changed their name to bridgstone because they've had so many recalls over the past 80 years that people started getting a clue. I'd invent the wheels myself but I know I'd probably get hit with a piano on the way to the patent office. I'd call them Lux-O-Glides or maybe X-Flats-O-Matix.

Re:More expensive tires that need replacing often (1)

mindbooger (650932) | more than 4 years ago | (#33260848)

Actually, Michelin did sort of what you're asking for a few years back -- the TWEEL. []

Apparently it hasn't been all that disruptive. At least not yet... :)

Re:More expensive tires that need replacing often (1)

r0kk3rz (825106) | more than 4 years ago | (#33260994)

Looking at the article I thought "Great! Whats happened since 2005 with these things?"

It turns out they vibrate horribly causing excess noise and heat at speeds of 50mph or more.

hmmm (2, Insightful)

thatskinnyguy (1129515) | more than 4 years ago | (#33260736)

It's like dragging a car sideways to the tires for many miles. In what universe does this make sense?

Re:hmmm (0)

Anonymous Coward | more than 4 years ago | (#33261002)

No, that'd be toe-in or -out.

Horrible for performance (0)

Anonymous Coward | more than 4 years ago | (#33260786)

These tires are a terrible idea in terms of handling and performance.

Tires produce the most grip when they are at zero camber, the problem is that when you are using all of that grip your car is rolling quite a bit, which adds positive camber to the outside wheel (where all of the load is being carried). Therefore, to produce a performance car you want your camber such that at full load the static negative camber from your alignment balances out the positive camber gained through body roll. A conical tire simply adds positive static camber, which just makes things worse at full cornering load.

I could see a small market using these tires backwards to gain negative camber on McStrut cars, which have terrible camber curves and can almost never get enough static negative camber.

Oh yeah, and a conical tire doesn't roll in a straight line, so be prepared to play endlessly with your toe-in to get it handling correctly again.

Wouldn't the wear / resistance actually be worse? (1)

Paco103 (758133) | more than 4 years ago | (#33260898)

Performance cars and race cars don't care much about tire wear, and it's well known that negative camber improves cornering. However if you look at the article they show a tire of "continually decreasing diameter", allowing a negative cambered tire to maintain a flat contact patch with the road. This means different parts of the tire have a different lateral speed when moving in a straight line. Even though it may be microscopic amounts, the tire would be creating continuous additional drag and tread wear.

As for performance, my real world experience is limited to 1/10 RC cars, but part of the benefit was that in cornering as the car rolls the contact patch of the outside tire is increased, which this tire would also negate. My pan (on road cars) always had hard suspension and practically no camber, while my off road cars with soft suspension benefited from more negative camber. If someone has more expertise to offer, I'd love to be educated.

And as usual, the Japanese... (3, Informative)

wickerprints (1094741) | more than 4 years ago | (#33261066)

have to take it to the logical extreme: []

Pretty soon, all stock Toyotas and Hondas will look like this! XD

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?