How much does wheel weight affect performance?

[srt4evah]

Originally Posted by Slammillionaire

Based on the info in this thread, I'm probably gonna pick up some 17x9 gramlights. Thanks guys! lots of gr8 info.

I ended up with Motegi Traklite MR131's, 17x7 with 215 rubber. But I like to slide.

MR131's are 17.5lbs in that size, and $455 shipped to your door off Ebay, hard to beat that for perf/$.

[Slammillionaire]

Originally Posted by srt4evah

I ended up with Motegi Traklite MR131's, 17x7 with 215 rubber. But I like to slide.

MR131's are 17.5lbs in that size, and $455 shipped to your door off Ebay, hard to beat that for perf/$.

I'm really trying to stay away from motegi, xxr, rota etc. The only rep company i would consider going with would probably be varrstoen.

[srt4evah]

Originally Posted by Slammillionaire

I'm really trying to stay away from motegi, xxr, rota etc. The only rep company i would consider going with would probably be varrstoen.

I am sure there may be people concerned about quality, but I've never broken a rim in a couple dozen cars I've had rims on (I'm 41), and frankly this entire SET of rims costs less than a single Advan. I could buy 2 sets of these for the cost of an RGII.

[Slammillionaire]

Originally Posted by srt4evah

I am sure there may be people concerned about quality, but I've never broken a rim in a couple dozen cars I've had rims on (I'm 41), and frankly this entire SET of rims costs less than a single Advan. I could buy 2 sets of these for the cost of an RGII.

Yeah but most reps look horrible and that's mainly my issue with them other than weight.

[srt4evah]

Originally Posted by Slammillionaire

Yeah but most reps look horrible and that's mainly my issue with them other than weight.

I will admit I don't really like the +45 look on these 17's, it's not terrible but it's not sexy, but they look better than stock imho and they're lighter. Suits my purposes, but everyone's got different plans.

I really absolutely love the look of a nice set of 18s on the 86, but I just don't want to spend the $$$ on lightweight 18's and new rubber.

[Byte11]

A gallon of gas weighs ~6.5 lbs. The FR-S has a 13.2 gallon tank. That means that a full tank weighs 85lbs more than a car without fuel. The full set of 15lb tires weigh 60lbs, so a full tank is like carrying around an extra set of light to medium weight tires. The difference between the 26lb heavy tires and the 15lb light tires is an additional 44lbs on the car.

Let's say you have half a tank of gas in your car, that means that you have 42.5 lbs less weight than you would with a full tank. That's basically the difference between the heavy and light tires you mentioned. So ask yourself: can you tell the difference between driving around with a full tank vs a half tank?

For me, the answer was a definite no.

[monkeybike]

That's not how it works.

[churchx]

Byte11: differences between sprung, unsprung, and unsprung rotational masses and impact of lightening of those. I changed stock wheels (9.1kg each) to aftermarket ones of 6.2kg weight. The difference wasn't great (sometimes seeing it overexagerated), but i could feel it by 'butt dyno', how car accelerates/how suspension works over road defects. It may not be among best price/performancy investments, but if one seriously takes on lightening everything, certainly one of worthy application points.

[new2subaru]

Originally Posted by Byte11

A gallon of gas weighs ~6.5 lbs. The FR-S has a 13.2 gallon tank. That means that a full tank weighs 85lbs more than a car without fuel. The full set of 15lb tires weigh 60lbs, so a full tank is like carrying around an extra set of light to medium weight tires. The difference between the 26lb heavy tires and the 15lb light tires is an additional 44lbs on the car.

Let's say you have half a tank of gas in your car, that means that you have 42.5 lbs less weight than you would with a full tank. That's basically the difference between the heavy and light tires you mentioned. So ask yourself: can you tell the difference between driving around with a full tank vs a half tank?

For me, the answer was a definite no.

Yes

[why?]

Originally Posted by Byte11

A gallon of gas weighs ~6.5 lbs. The FR-S has a 13.2 gallon tank. That means that a full tank weighs 85lbs more than a car without fuel. The full set of 15lb tires weigh 60lbs, so a full tank is like carrying around an extra set of light to medium weight tires. The difference between the 26lb heavy tires and the 15lb light tires is an additional 44lbs on the car.

Let's say you have half a tank of gas in your car, that means that you have 42.5 lbs less weight than you would with a full tank. That's basically the difference between the heavy and light tires you mentioned. So ask yourself: can you tell the difference between driving around with a full tank vs a half tank?

For me, the answer was a definite no.

That is not how the math works. That weight in the gas tank is not being rotated, so its effect is a lot less.

The less rotating parts weigh, the better. If that was not the case no one would buy RPF1's

[TommyW]

Originally Posted by Byte11

A gallon of gas weighs ~6.5 lbs. The FR-S has a 13.2 gallon tank. That means that a full tank weighs 85lbs more than a car without fuel. The full set of 15lb tires weigh 60lbs, so a full tank is like carrying around an extra set of light to medium weight tires. The difference between the 26lb heavy tires and the 15lb light tires is an additional 44lbs on the car.

Let's say you have half a tank of gas in your car, that means that you have 42.5 lbs less weight than you would with a full tank. That's basically the difference between the heavy and light tires you mentioned. So ask yourself: can you tell the difference between driving around with a full tank vs a half tank?

For me, the answer was a definite no.

Go out and tape 44 lbs of lead weights on your wheels, go drive the car and report back.....

[dattran86]

Me, a guy swap wheel every 2 weeks for racing events. went from stocker to 17x8 GTF1, which is 15.6 lbs per wheel. wrapped in 225s. back and forth like 15 times

I do noticed the difference in accelerating. the car just feel "lighter".

my recommendation...sound like you got alot of money to throw at it, go for 17in RPF1, Wedsport TC105n, or even those cheaper GTF1 720 Flowform perform extremely well.

I've ride curb on race track with GTF1 and they held up pretty well.

[PeterFRS]

since OP said won't be tracking the car at all,
i say go for the ones you like based on looks.
sure you can run with your asics - but you can also run with timberlands as well.
feel heavier? sure but if youre not gonna track, i say rock those tims

[Twinz]

The way I view it, for acceleration at least, is that wheels are basically levers. Making the wheel heavier is like using a heavier lever and where the weight is added on the lever *technically* makes a difference, but when each of the two rear "levers" are responsible for moving over 1300lbs, I don't know that adding 5 lbs anywhere on the lever makes an appreciable difference.


I think the gyro effect may be noticeable when turning the front wheels, but the bulk of resistance to forward motion comes from the mass of the car itself and small changes in wheel weight seem like "noise" when compared to the primary mass they must move. (In a straight line at least)