S4 rims effect performance?
 

I just got my car back from the dealer (it was in for a check-up) and they told me my tires would need to be replaced in about 1000 miles, and the way I drive it's gonna be alot less. So I was thinking of getting those new BBS CK rims in 19x8.5 since i'm replacing the tires soon anyways. Will the increase in diameter and tire width slow my car down? I'm not conserned with anything accept acceleration from 0-90 or so. Also, does anyone know what the weight is on the BBS CK? Tirerack doesn't have it listed.

RE: S4 rims effect performance?
 

Not sure about the ck...ch in an 18x8.5 is 27lbs....19's look good but I'd stay with 18s for performance and ride characteristics.

RE: S4 rims effect performance?
 

What "ride characteristics" are going to be effected? Are we talking like handling, or just feeling more of the bumps in the road? I'm not sure how big the difference would be cuz the stock rims are 18s. My dad said if I got 19s and he liked how they felt hed replace the 18s on his RS6 for some 19s as well, should we both just stick with the 18s? Both my dad and I are willing to feel a few bumps if it improves the look of our cars. Also, I didn't quite understand your response, you said stay with 18s for prefomance and ride char. do you mean performance like acceleration? And if so would the 19s affect it much (like more than .1sec on the 0-60?

RE: S4 rims effect performance?
 

Probably won't be much of a difference, if any, especially if going with a lighter wheel. The problem with going to a larger diameter wheel is that you push the weight of the tire further and further from the center which increases parasitic power loss. (There's a reason most drag racers still use 15" wheels...) You also need to take into account the weight of the new tires that you'll be mounting as compared to the old ones. This is one of those "not enough information to be entirely sure" type deals, but if I really liked a set of wheels and wanted to go to 19's, I'd be willing to sacrifice a tenth to 60.

Peter

RE: S4 rims effect performance?
 

Good points WillworkforS4. I have 3 sets of wheel/tire combos for my S4 (though am actively only using 2 of them). I have 2 19" sets - one set of Supperleggaras with Toyo Proxis and another 19" set of RS4 replicas with Yoko AVS..I also own a set of 17" A4 sport rims with Vredstein Wintrac performance snows and each - of course - gives me different ride and acceleration feel. The Supperlegaras are very light (18lbs - forgot exactly) - and acceleration is definately quicker and handling (steering feel at least) feels lighter...they do however convey road bumps and such more and give a rougher ride. The 19" RS reps make the car feel more stable/grounded on the road - grip is better (those Yokos are awesome!) and they cushion a bit more - but off the line acceleration is noticibly less - just a bit less initially explosive. The 17" Vreds are awesome - particularly for snows - but the larger sidewalls are noticible with some lean/wobble in high speed cornering. Of course they cushion much better - have some degree of extra road noise - but not bad - and have really surprised me on how little I sacrifice in terms of grip and overall performance in regards to the 19" (summer performance) wheel/tire combos. So yeah - each gives the car a different feel - and to some degree I would caution with the lighter wheels for everyday driving (as i kept dinging, bending and even cracking them on various road circumstances where the heavier/sturdier wheels have held up much better on the same pavement). Also the heavier wheels - while perceptibly giving a bit of an acceleration penalty (don't know exaclty how much - but I can tell) actually give the car a more sturdy and planted feel on the road and seem to corner better (though much is tire grip I imagine) - could it perhaps be more weight down low is also making a difference there - don't know. Anyway - hope this was helpful.