V6QuattroFanatic

I've searched forum, but finding advise specific to my setup is hard.

I have a '99.5 A4 w/ neuspeed sport springs that have a 1.25 inch drop front and rear. I've put in S4 Koni adjustables set pretty stiff and a neuspeed rear sway bar.

I want to upgrade to 17 inch rims from stock 16s. I want as wide a tire/rim combo as I can get w/o fender rub. How wide a rim should I get? I see a lot of people are running 225/45/17's. Is that a good tire size for max grip w/o having to re-calibrate the speedo? I'm in it for performance, not looks. I'm also not worried about caliper clearance b/c brake upgrades will only include rotors/pads/lines. Any recommendations would be great. Thanks!

ex-quattro PETE

Yup. 17x8 with 225/45 tires is a pretty safe bet, and good for grip if you get some sticky rubber.

::Relapse::

and you have the same footprint with a lighter wheel

ex-quattro PETE

7.5" is fine, too. With 8" the tire sidewall is a bit more straightened out resulting in less sidewall flex during hard cornering, but the difference is marginal.

V6QuattroFanatic

but that does pose another question: how much of a difference will I notice (positive or negative) going from 16X7 to 17X7.5? I would think that bigger rim + smaller tire profile = tighter handling, but someone I know that road races said "stick w/ the 16" rims if you can fit 225's on them". He sait that the smaller rim is desired for road racing.

I'm in it for performance, looks are just a side thing. Would it be worth the $$$ to go up to 17's? Also, could I fit 235's on the 17X7.5 for more contact?

If the difference between 7.5" and 8" isn't noticable as far as sidewall flex, how much of a difference is there w/ a 225 tire on the 16X7 and the 17X7.5? (Noticable, I assume, b/c of straightened sidewall AND lower profile sidewall).

In short, is it worth the $$$ to get 17's from a performance standpoint?

To aid in answering, I drive my A4 as a daily driver, but I like to AutoX with it and do open track events when I can.

ex-quattro PETE

the rule is to use the smallest rims that will fit over your brakes. Of course, for serious performance you'd also have big brakes, so that automatically means you can't use small rims.

The idea of going with a rim that's as small as possible is that it weighs less. The improvement of the car's acceleration/braking is more important than the slight decrease of steering response due to taller sidewall of tire that sits on a smaller rim. Besides, you can get some dedicated track tires with very stiff sidewalls and it'll take care of the steering response for the most part.



<i>but that does pose another question: how much of a difference will I notice (positive or negative) going from 16X7 to 17X7.5?</i>

You should notice some difference definitely. I know I do. Whether it's a lot or not - well, that's personal perception I guess.

<i> I would think that bigger rim + smaller tire profile = tighter handling, but someone I know that road races said "stick w/ the 16" rims if you can fit 225's on them". He sait that the smaller rim is desired for road racing. </i>

Road racing? Who does that? Hopefully you meant track time. :-)

<i>I'm in it for performance, looks are just a side thing. Would it be worth the $$$ to go up to 17's? </i>

17s are generally a good balance of looks and performance in my opinion. If you don't care about looks, stick with 16s.

<i> Also, could I fit 235's on the 17X7.5 for more contact? </i>

Depends on the rim's offset and how much lowered your car is. To properly stretch a 235 tire you should get an 8" wide rim though, IMO. Offset around ET35 should be good.


<i>If the difference between 7.5" and 8" isn't noticable as far as sidewall flex, how much of a difference is there w/ a 225 tire on the 16X7 and the 17X7.5? (Noticable, I assume, b/c of straightened sidewall AND lower profile sidewall). </i>

Yes, generally going from 205/55 to 225/45 is more moticeable because you're cutting down on sidewall height. But do take my other point into account - that you can get a 205/55 (or 225/50) track tire that will be as stiff as a 225/45 street tire.

<i>In short, is it worth the $$$ to get 17's from a performance standpoint? </i>

Depends. Assuming you can get 17s that are as light or lighter than your 16s, I'd say yes, but that's going to cost you quite a bit $$$$.

<i>To aid in answering, I drive my A4 as a daily driver, but I like to AutoX with it and do open track events when I can.</i>

I'd look for some strong and lightweight 17x7.5 or 17x8. And in case you decide to eventually upgrade your brakes (I know you're not planning on it now), you'll have the room.

V6QuattroFanatic

THX for the help PETE!