Realistically, how much does wheel weight affect performance?

[DriftwoodSVT]

I'm in the market for some 18x9.5 wheels. I've seen everything from 17.3 lbs all the way up to 26.3 lbs.

At 9 lbs per wheel more, that's a 36 lb total difference in rim weight. Can one honestly expect to feel or see a performance difference with 36 lbs? Or would it be very minimal?

Just curious more than anything. :beer:

 

[BlckBullitt01]

I think theres a general estimate to multiply rotating weight x10, so 36 lbs. rotating weight would have about the same effect on accel. as a 360 lb. person in your backseat.

 

[Cobra Was Here]

The rotation radius is going to have a bigger influence when combined with the additional weight that comes with it. How about we get some Dr. Snover info in here?

 

[greenstang1313]

correct me if I'm wrong but Ive heard that 1lb on a rim is equal to 10lbs of rotating mass. So at 9 extra lbs per rim you're talking about 90lbs of rotating mass per wheel. A total of 360lbs of rotating mass. You will absolutely notice a difference.

 

[DriftwoodSVT]

wow, 10 to 1 is a big difference. I honestly didn't think it was quite that much.

 

[Sarge_13]

wow, 10 to 1 is a big difference. I honestly didn't think it was quite that much.

Don't forget the extra weight from the rubber you need on the wider wheels.

 

[LaFlavor]

The weight is also unsprung. Really, the wheels are one of the very worst possible places to have extra weight, since it's unsprung and rotating.

 

[Blackness03]

put a set of superswamper tires same size as stock and youll notice it right away HUGE diffrence

 

[mustangvsix]

good lord, I knew wheel weight had a decent effect but good lord that is much more than I ever thought.

 

[James Snover]

Got it dead right. Not only are they one of the worst places to have weight, the faster they spin, the more they affect the handling, and effectively, the more they weigh. And it is not linear, it is exponential. Add in gyroscopic forces, precession, and sometimes I wonder how in the hell five bolts are enough to hold the things on.

Guess what else? You know why you don't see ultra-low profile tires on racers? Because the metal weighs more than the rubber, in most cases, putting more weight and more kinetic energy and precessive forces right where you absolutely most do not want it.

Jim Snover

The weight is also unsprung. Really, the wheels are one of the very worst possible places to have extra weight, since it's unsprung and rotating.

 

[03CobraBro]

Unless you plan on tracking your car I'd be less concerned about the weight of your wheels and more concerned with ride quality, because that's something you will definitely sacrifice if you end up driving down a rougher road, not to mention a heavier rims durability for day to day use. Best bet is to have 2 sets.

 

[u n v kenny]

My 18x10's are 33lbs each
18x9's are 30lbs each

plus tires... That's a lot of weight

 

[DriftwoodSVT]

Got it dead right. Not only are they one of the worst places to have weight, the faster they spin, the more they affect the handling, and effectively, the more they weigh. And it is not linear, it is exponential. Add in gyroscopic forces, precession, and sometimes I wonder how in the hell five bolts are enough to hold the things on.

Guess what else? You know why you don't see ultra-low profile tires on racers? Because the metal weighs more than the rubber, in most cases, putting more weight and more kinetic energy and precessive forces right where you absolutely most do not want it.

Jim Snover

Good info, thanks for the comment :beer:

 

[HYBRED]

Got it dead right. Not only are they one of the worst places to have weight, the faster they spin, the more they affect the handling, and effectively, the more they weigh. And it is not linear, it is exponential. Add in gyroscopic forces, precession, and sometimes I wonder how in the hell five bolts are enough to hold the things on.

+1

Weight is a force. The simple formula to calculate the centrifugal force induced by a spinning object is Fc= mv^2/r. Increase the mass, increase the force. Go faster, increase the force exponentially.

 

[virginiafiveo]

ok...so, similar to performance, I would imagine this has a similar effect on gas mileage as well. and handling to an extent. now...example. stock 10th anniversary wheels are 23.8 lbs. where the same size rim from Enkei weighs 15.9 lbs. how much of a difference would be seen in the 1/4 mile and in gas mileage would you say Mr. Snover? I'm guessing 1-2 or so right?

 

[SpectorV]

it makes a big difference, as said above its about 10 dead weight lbs = 1 lb of rotating mass. That's why two piece rotors are nice to have, the centers are lighter weight.

 

[James Snover]

In terms of mileage you may not notice any difference, since mileage is best at a steady cruise, and once you get the wheels of either weight up to cruise, the power to maintain it is about the same. And since most takeoffs from a red light are not max-performance, you may not see a big change in mileage. Aerodynamics play the largest role at speeds over 35mph in terms of mileage.

1/4 mile performance is a different matter. Lighter weight wheels, all things being equal, give better times. But again, the catch is the "all things being equal," which in this case means (no offense) "Are you a good enough driver to capitalize on the difference?" For most of us who aren't really skilled with the right foot, it probably won't make much difference, but it does raise the ceiling of of what can be done.

Jim Snover

ok...so, similar to performance, I would imagine this has a similar effect on gas mileage as well. and handling to an extent. now...example. stock 10th anniversary wheels are 23.8 lbs. where the same size rim from Enkei weighs 15.9 lbs. how much of a difference would be seen in the 1/4 mile and in gas mileage would you say Mr. Snover? I'm guessing 1-2 or so right?

 

[sunburned]

I recently saw a black Z4M coupe with Volk TE37 Time Attack wheels (black with red lip) and it looked so badass. I'd recommend those because they are light as hell and look good too.

 

[Phallen]

Rotating mass makes a big difference, ESPECIALLY when you're accelerating past 100 mph. With lighter rims/tires, the car doesn't feel so 'weighted down' as much when you're doing a ton plus.

 

[SnkBtn99]

Weight is weight and DOES make a huge difference. Sprung or unsprung.