Hey guys,

I just ordered some PIAA Super Mesh wheels, 19x8.5. PIAA recommends a 235/35 tire and I see S4s with 245/35 and there are a lot of other wheel manufactures that recommend 245s. My question is, if I go with 245/35 will I get rubbing? I take clients out daily and this is my only car, so I can't have any rubbing and I don't want to deal with rolling the fenders, the car is not lowered right now?

Also, I want the extra rubber, but am I going to notice a difference between a 245 and a 235? I noticed a difference on my last car, but I see people here saying they can't tell the difference.

Any info would be great, thanks for the help!

 

What year is your car?
What size are your current wheels?

The difference in 235/45R19 to 245/45R19 is really small...like maybe 1/2 inch.

 

the difference is exactly 10mm. lol. But get 235...

 

I have a B6, I did put the 235s on. Not as wide of a look, but I just took the car through a great section of road and no scraping......which I am happy with.

 

10mm circufrance? Cuz I'm talking total Diameter of the tire which is what would affect wheel fitment the most.


also...i suck at speeling!

 

Uhh the numbers arent arbitrary, they are the tire dimensions.

235/40ZR18 for example

235 - width of the tire, sidewall to sidewall, in mm
40 - ratio of sidewall height compared to width of the tire (as a percentage) 40 = 40%. 235(mm) x .4 = 94mm high sidewall
ZR - speed rating, this letter varies depending on the type of tires
18 - Wheel diameter, 18"

thats why theres a 10mm difference in width of the tire from 235mm wide rubber to 245mm wide rubber. Also when you go to a 19" wheel the ratio of sidewall decreases, so the overall diameter of the wheel and tire dosnt change as much.

We know 235 will fit, some people get 245 though. When i bough my car it had 245s on it, I drove with them for a full year. I got great traction, driving normally no noticable rubbing, but under hard braking or turning yes they did rub. If rolling my fenders solves this problem, thats what ill do, Or maybe ill just decide to get 235's......

If you dont want to roll your fenders or deal with rubbing go with a 235 tire. And honestly yeah there is 10mm less surface contact on each tire, but im not so sure you would notice it that much, especially with the stock suspension. What kind of car did you drive before your audi that the difference was so apparrent?

Edit: Its not nessicarily the diameter of the wheel and tire combo that causes issues. Its the WIDTH. Thats why theres issues with a 255/40zr 18 and not a 235/40zr18. As the diameter of the wheel increases from 18" to 19" you buy tires with a lower ratio of sidewall to width. Take for example the tires earlier, that wheel/tire has 94mm of sidewall on each side of the wheel. By increasing your wheel to 19" you have increased the total diameter of wheel/tire by 1". However you new tires have 235/35zr19 markings. 235(mm) x .35 = 82 mm. That means there is 12mm less sidewall on each side of the wheel, where you gained 1" of wheel, you lost a total of 24mm (.94") of sidewall. It all evens out, But if your tires are wider, you dont make up that width anywhere (unless you roll your fenders to make more room)

 

ummm... not sure, but i'm pretty sure the 19x8.5 will not fit on that car.... my buddy and i just put some 19's on his 01 a6 and we had to modify the suspension for the wheels to fit......

 

HP addict.. nice work, youre dead on.. YEs, the issue with rubbing comes from width.. i always adivse dont go above 235 on ANY size tire.. 17,18,19, they most likely will rub. it is possible to get bigger to work.. but youll prob get some rubbing.

as far as dimensions and waht not.. under normal driving... or even spirited driving on the street, youre not really gonna notice much difference between 235 or 245

 

Ya know I don't know why I totally spaced that. Especially when I had to change the backspacing for my lifted Ranger when I went with 33x12.5 BFGs. Anyway, I'm pretty sure there's a tiny difference in how tall the tire is too when adding the extra rubber to the same size wheel. That's where I'm thinking the extra 1/2 inch comes from.

Anyway, I'm running 225/45ZR-17...so what do I know other than those fit! =D

Good posting HP Addict.