Aclarke

Obviously lighter wheels mean faster car... but when are wheels too light? Are light wheels the sign of a junker?

I am asking this because I am looking to replace my OEM 17" IS 250 wheels with Ace Arius 17"... according to my research there is about a 4 lb difference per rim. Should I be concerned that these wheels might be prone to bending or something while driving in the NJ/NYC metro area? Thanks.

LexFather

1. Never heard of Ace rims.
2. A 4 lbs difference X 4 wheels is 16 lbs, that is not a bad difference.
3. Its more than just a faster car, less weight on the supsension is called less "unsprung" weight, which greatly can affect the handling characeteristics of the car. The less weight, the better your car will handle. That is why you will see some sports car makers and auto companies go through great lengths to offer light forged wheels and large light brakes.
4. Wheels can never be too light, as lighter wheels are usually made by companies and are some of the strongest wheels possible, due to the forging process.
5. However, with everyone going with bigger and bigger wheels, its harder to lose the weight

Hope this helps.

rominl

iTrader: (4)

actually, 4lb is HUGE difference especially when you talk about 17s still. for example, stock gs400 wheels are around 25lb. hre 20s, they are 25-26lb, some cast 20s they are around 30lb, though i have seen stupid 20s that weigh at 40lb as well. so if you are still at 17s, it's heavy.

there is no "what is too light", it depends on constructions, materials, etc... for example the volks racing te37 17s, i think they weigh in the 17-18lb range. but it's still good strong wheels.

and lightis good since it helps BOTH acceleration and braking.

bottom line is you need good quality wheels from good company. regarding ace, i have no idea

Eternity3G

Keep in mind unsprung weight! I don't remember what the exact ration is, but I THINK it's 7x's. SO...

4 puonds more per wheel x's 7 = 28lb
28lb/corner x 4 corners = 112lb in the car....

No bueno... kick the "extra chick" outta the car!

Here's a reference:
"Ignoring the flexing of other components, a car can be modelled as the sprung weight, carried by the springs, carried by the unsprung weight, carried by the tyres, carried by the road. Without the unsprung weight, the force of a tyre on the road would come from the vehicle weight and motion, transmitted by the spring. But the unsprung weight is cushioned from uneven road surfaces only by the springiness of the tyres (and wire wheels if fitted). To aggravate this (for fuel economy and to avoid overheating at high speed) tyres have limited internal damping. So the "wheel bounce" or resonant motion of the unsprung weight moving up and down on the springiness of the tyre is only poorly damped, mainly by the dampers or Shock absorbers of the suspension. For these reasons, high unsprung weight reduces road holding and increases unpredictable changes in direction on rough surfaces (as well as degrading ride comfort and increasing mechanical loads).

This unsprung weight includes the wheels and tyres, usually the brakes, plus some percentage of the suspension, depending on how much of the suspension moves with the body and how much with the wheels; for instance a solid axle is completely unsprung. The main factors that improve unsprung weight are a sprung differential (as opposed to live axle) and inboard brakes. (The De Dion tube suspension operates much as a live axle does, but represents an improvement because it is lighter, thereby reducing the unsprung weight.) Aluminium wheels also help. Magnesium wheels are even lighter but corrode easily."

Aclarke

These are the wheels that I was alluding to... Anyways, they are available on customwheelsdirect.com. I know of two people who had Ace wheels on an IS300 and even an A4, but both care more about looks. My main concern, as shown by this thread... is quality. The Ace alloy wheel website is www.acealloywheel.com

If there is a wheel of better quality from a more reputable brand, I would love to hear suggestions. Once again, I don't want to change out of 17" wheels because the AWD makes the car look like its already on stilts... dont want to raise the ride height even more.


But back to wheel weight...
Am I wrong in saying that wheel weight does not necessarily correlate to wheel strength?

Thanks for all your help and advice

LexFather

You are right, 4 lbs is a huge deal, my bad

LexFather

Great post

LexFather

I have seen those on an IS, they do look good

Aclarke

What kind of difference will it make going from 17x8 stocks to these Ace's which are 17x7.5... How concerned should I be about offset? and will these new aftermarkets fit my stock 225/45/17??? Thanks.

Eternity3G

depending on width and offset, the wheel will move in or out (in respect to horizontal fender well movement)

A 7.5" wheel will still work with the 225, but the tire will present a more "bubbled" look.

If you shrink a 8.0" down to a 7.5", than the face of the wheel will sit in the same place if the offset drops 5mm. if it drops more than 5mm, then the face of the wheel will move out towards the fender more and vice versa.

i.e. a 18x7.5 et34 vs 18x8.0 et40 will roughly sit in the same position in respect to the face of the wheel to fender clearance

I personally don't believe in shrinking widths from OE to aftermarket though. Try finding a 8.0" or 8.5"...