Best C36 Wheel Size for Race

[Oops2Fast]

Hi all, what is the best wheel diameter for race / time attack? Is 17" too big for C36? 15" is too small?
I'm using 18" right now and have been told it's too big.
Thanksss..

[JayRash]

Well car came with 17in from factory
and for sure 15in is small.

now with 17in the car is setup as compromise between ride and handling. as it is in 18in ur car should be gr8 for handling subject correct tire size is maintained.

ie: car came with 225/45/17in front
245/40/17n rears

correct size for 18in:
225/40/18in
255/35/18in

[Oops2Fast]

Why is 18" handling better? Isn't the 17" has lighter usprung weight thus should has better handling?

[JayRash]

That is not always the case, some after market 18in ar lighter than merc 16in', any way if weight diff is minimal ie 18in are not seriously heavier than the stock 17in then the handling is better for 18in due to lower side wall of the tires meaning less deflection ie better steering and more stable under braking.

[Turbo E320]

Mercedes arent the lightest cars in the world so I would run 18s.

[whipplem104]

First I do not think that you can go under a 16 over the front brakes. It might be 17. I would go for 16. Personally if they will fit. The '98 clk rims were super light and you can get them super cheap. You want some tire side wall. Race tires if you get them have a pretty stiff side wall. I would not go over 17.

[JayRash]

@whipp. My assumption was that the car is a daily drive to have some fun at the track. But 16 in from the 320s w220 iirc , the ones that look like those of the clk w208 should clear the fronts as the s class has 4 pot brakes. They r abt 13lb each. I have a set of the 15in from the slk200 they are 9lb each. I know cause i have weighed them. Those will fit with a spaces but are useless unless u go with yokohama semi slick, one of their tires came in 205 / 60, the only one i could find.

[Johnhef]

Originally Posted by whipplem104

The '98 clk rims were super light and you can get them super cheap. You want some tire side wall. Race tires if you get them have a pretty stiff side wall. I would not go over 17.

I run them on my track events just for that reason. they are however not enough for my SEC and I went up to 275/17's. For my 124, (basically same as your C36) it was plenty and they worked well with it.

[Chlippo]

I got 18inchs SL rims on my Ex-C36,
you will love the handling but the front tires will barely fit in there...
if you go hard on corners the tires will touch the bumpers

[Oops2Fast]

Originally Posted by whipplem104

First I do not think that you can go under a 16 over the front brakes. It might be 17. I would go for 16. Personally if they will fit. The '98 clk rims were super light and you can get them super cheap. You want some tire side wall. Race tires if you get them have a pretty stiff side wall. I would not go over 17.

Why would you go for 16? Besides lighter unsprung weight, what are other advantages/disadvantages running on smaller diameter rims?

[whipplem104]

Weight, weight, weight. I think a 17 would be fine if you got a forge wheel that
fit the car. I do not know which would be better, given the same size tire. It depends on how the suspension behaves. My point is really that the thinest side wall is not the best and getting ride of unsprung weight instead of adding it is the way to go. Honestly, I would look at what similar cars run. I just suggested the 16" because they are cheap and light and with a properly sized track tire would work well.

[Oops2Fast]

Originally Posted by whipplem104

Weight, weight, weight. I think a 17 would be fine if you got a forge wheel that
fit the car. I do not know which would be better, given the same size tire. It depends on how the suspension behaves. My point is really that the thinest side wall is not the best and getting ride of unsprung weight instead of adding it is the way to go. Honestly, I would look at what similar cars run. I just suggested the 16" because they are cheap and light and with a properly sized track tire would work well.

I finally bought a set of new 17" BBS RC that was on sale on local shop. It felt light when I tried to lift it. Performance wise, I couldn't tell any different with my 18" AMG. Only braking seemed better. And with 17", the tire has thicker side walls that seems absorbed bumps better, so on bumpy turns, the car handling was better also.