So I was looking at getting the Avant Garde M310 wheels in 19's, and noticed how much heavier they are than my style 124 wheels.

The front 124 is 24.8 and the rear 124 is 24.9

The Avant Garde wheels I am looking at for the front are 25.7 and the rear is 31.

If these numbers are correct and when you do the math with "1 lb of unsprung weight is equal to 10 lbs of static weight", then that means static, a set of M310 would be 140 lbs heavier than the 124 wheels- 18 lbs heavier front, 122 lbs heavier rear.

Is that enough extra weight to be noticed?

I am also looking at the Forgestar F14's in the same sizes as the Avants. The F14 is A LOT lighter.

Front is 23.4 and the rear is 25.7....so that means static, the front is 28 lbs lighter, and the rear is only 16 lbs heavier than the stock 124's.

I would think this would not be noticed.

Am I putting too much thought into this or would the weight of the Avants actually be noticed in terms of car performance; handling, acceleration, braking, etc?

On a side note, are non runflats any lighter than runflats? I'm assuming I will be saving weight when I go to non runflats

Thanks for any insight....

 

Tire weights too make a difference. My wheels are 26lbs but my tires weigh in at 21lbs fr and 23lbs rear...The ones I just took off were 24lbs front and 26 rear. It will make a difference in acceleration and MPG There is a great 3 pages on the m5boards.com just search in Google for WSTO weights, they did rim weighing of some major brands. In your case on the 124's you can drop some weight just by switching to a non runflat. Keeping the wheel/ tire weight under 52lbs is a definite plus


Try to find rims that are in the 18-23lb range along with tires and your 550 will accelerate better.

 

I think you're mixing concepts.

Unsprung weight affects how quickly the suspension reacts. That's a linear relationship, but remember that includes all the stuff that moves (i.e. brake discs, steering knuckle, control arms, lower shock, etc), not just the wheel. The main thing here is the weight ratio of what's moving to what's not moving. Much bigger deal on a motorcycle, which is why you have things like inverted shocks. Not so much on a car.

The overall inertia penalty on acceleration is >1:1. It's not 10:1, more like 2:1, the exact number depending on how the weight is distributed from center of the wheel. Remember the brake disk turns here as well.

Overall, we're talking about changes in the fractions of a percent range. I wouldn't make weight my primary decision maker.

 

Un-Spung weight is a bigger deal when it comes to performance and handling. Although there seems to be a pretty big Delta between your two options my guess is you will not "feel" a difference. Remember you are talking a bout a 2 ton sled here, not a track car.

 

Good point......

I do know that a lightened flywheel that weighs 12-15 lbs makes a pretty big noticable difference when compared to an oem flywheel that weighs 40-50 lbs. We're talking turbo Nissans here, not BMW's though.

 

don't know, this is what the rep at Mod Bargains told me- 1 lb of unsprung weight is equal to 10 lbs of static weight

 

Fly wheel is completely different than unsprung weight. & Yes a lighter flywheel makes a big difference in performance cars.

 

Yeah, and the guy at Discount Tire told me the $280 tire with a 260 wear rating would last longer than the $150 tire with a 320 wear rating. Their job is to sell you, often using data and 'fact' talking points they might believe in but in reality are overstated or simply not true. Caveat emptor.

 

Very true.....but I would think a noticeable difference would be felt between a wheel that weighs 25 and one that weighs 31. Your right, it's not a track car, but I don't want it to be any slower than it is. If this will be the case, then I'll have to pass on them

 

We're talking about an acceleration difference of less than 1%. If you can notice that, I've got some mattresses and a pea for you to test out. ;-)