Werks

I'm currently in the process of upgrading my stock C5 wheels to an 18/19 wheel package and had a couple of questions about tire sizes and possible issues with traction control. Looking at the stock tire sizes and diameters:

Fronts: 245/45/17= 652mm diameter
Rear: 275/40/18= 677mm diameter
So your looking at a F/R ratio of 1/1.038


Now the tire options I'm looking at with the 18/19 package are as follows:

Front: 275/35/18= 649mm diameter
Rear: 285/35/19= 683mm diameter
This gives you a F/R ratio of 1/1.052 or a 1.38% difference over stock.

The other alternative is going with a wider rear tire:

Front: 275/35/18= 649mm diameter
Rear: 295/35/19= 689mm diameter
This gives you a F/R ratio of 1/1.061 or a 2.27% difference over stock

Sooo after all of the math and a overwhelming desire for a frosty beverage what I would like to know is.....Do you have any experience with running any of the above tire combo's and if so did it result in any traction control related isssues??? Thanks in advance for the help I was literaly going running the numbers on all of these lol!

Y2Kvert4me

Either combo will work fine.


As long as you keep the rear tires at least 1/2" (12.7mm) taller than the fronts, you'll have no TC problems.

See, ya shoulda asked before doing all the math.

army2000

I . But go with the wider rear tire. It just looks cooler .

SS~7

If you go w/ a 19x11 rear wheel you can also go w/ a 305/30/19 tire ....

Werks

Thanks Guys! Wanted to avoid the issues that I read about one of the forum members having a while ago when he bought the wrong sizes! Off to order some new BFG KDW's now!!!

GKE

I have 305/35/19 on a 19x11 in the rear, beware....they will rub at the inner fender liner.

Wicked Weasel

that depends on the offset of the wheels. I run 305s on the street with no rubbing and I run 315s on the track with no rubbing (I also run 295 fronts on the track with no issues).

To the OP - why not go with 19s all around. I have run 17s, 18s, and 19s all around and the look of the 19s all around is sweet.