# Will 4 pound ligher tires make any acceleration difference?



## hyeedo818 (Mar 10, 2009)

I researched the weight of continental extreme DWs compared to all season contiprocontact the weight difference is 4 pounds
I read each unsprung pound is like 10 pounds in ur trunk
If I put 4 of the DWs will i be saving 160 pounds or is that just talk?


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## Airy32 (Nov 15, 2007)

Not sure of the specifics of your analogy but, 4 pounds in a tire is a pretty huge difference. It's not only unsprung, it's rotational mass. It will take measurably less force to accelerate, decelerate, and change direction. And should thereby also give better fuel mileage. Lighter weight wheels are a high priority for anyone seeking the best performance and handling. Lighter tires can make a more dramatic impact because the mass is further from the center than any part of the wheel.


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## hyeedo818 (Mar 10, 2009)

thanks
its for a 09 vw CC front wheel drive
will the theory you are stating about lessening the rotational mass only be effective for the drive axle wheels?


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## Airy32 (Nov 15, 2007)

No, the mass has to be moved (rotated) or stopped under braking and requires energy to do so whether it be on driven wheels or not. BTW I purchased a set of Continental DWs a few months ago and the weight savings was definitely a big factor. I'm on 245/35/19s at under 21 lbs each! Not many other tires in the same size are in the ballpark.


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## EuroSportChicago (Jun 9, 2010)

Yes, Less rotating mass = faster acceleration and stopping


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## Gesford (Sep 5, 2009)

but if its 4 pounds lighter you have less material which means they might not be as tough and you will be repplacing tires more often. gotta look at that stuff before you go swapping tires


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## Airy32 (Nov 15, 2007)

Gesford said:


> but if its 4 pounds lighter you have less material which means they might not be as tough and you will be repplacing tires more often. gotta look at that stuff before you go swapping tires


:bs: No offense, your statement may not be 100% incorrect. But with newer tire technology a lighter weight is most likely due to the use of lighter weight materials (such as kevlar and carbon fiber) and construction specs, not simply "less material". And it wouldn't necessarily make a tire less durable, in fact maybe the opposite.


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## EuroSportChicago (Jun 9, 2010)

Airy32 said:


> :bs: No offense, your statement may not be 100% incorrect. But with newer tire technology a lighter weight is most likely due to the use of lighter weight materials (such as kevlar and carbon fiber) and construction specs, not simply "less material". And it wouldn't necessarily make a tire less durable, in fact maybe the opposite.


x2


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## hyeedo818 (Mar 10, 2009)

my new tires are 2 lbs ligher than my old ones i dont feel any difference


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## vr6_nocorrectway (Jan 6, 2009)

if ur talking about taking 4 lbs out of each tire, wont make a diff. cuz u have less rotational mass, but the tire is more flat, leaving more tread on the road and causing more resistance


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## 10Ten (Sep 29, 2007)

i disagree. i lost 4 lbs per corner when i changed wheels, and i could certainly feel the difference. but my car is pretty setup, and small subtle changes are evident if i pay attention. not sure i'd feel a 2 lb. difference though.


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## [email protected] (Apr 9, 2008)

I'd say that if you have the 2.0 engine, a heavier tire might make the car just a little sluggish on accelleration. If you have VR6, it shouldn't make a noticable difference.


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## golf-zilla (Sep 5, 2004)

Back in '04 when I first got my R32, I swapped out the original Aristo wheels for VW/BBS RCs, still using the stock Goodyear V-tread tires. The RCs are about 5lbs lighter (each) than the Aristos. When I test-drove the car after the swap, I noticed a very definite improvement in ride quality on the very first bump I hit. I mostly drive like an old man, so I didn't check for other performance improvements, but I live in Newton's universe so I know they were there.

Air32 is right: eliminating rotational mass out past the rim (the tire), where it has the most effect (momentum/inertia) will give maximum performance benefit. Try to think of your wheels/tires as flywheels, because for the purposes of this discussion, that is _exactly_ what they are. Anyone can understand that it's easier to spin up or slow down a lighter flywheel than a heavier one. Less mass requires less energy to affect a change in rotational speed, period. And that's just in terms of acceleration and braking. What I alluded to above, the improvement in ride quality, will also apply to an improvement in suspension response just from the simple reduction in dead mass that the suspension has to control. Of course, this will also benefit your traction when traversing bumps in the road or on the track. So, killing weight/mass at the wheel/tire combination (especially the tire) will reap noticeable benefits in performance and ride/handling (on bumpy surfaces). Does that car actually perform like it's 160lbs lighter? Absolutely!


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