Question about rear tire size..

[Vette73]

CAN SOMEONE TELL ME THE DIFFERENCE BETWEEN 315-35-17 AND 325-35-19?

Im guessing of course the 325-35-19 is wider but how about the height? Came across a set of 2010 Grand sport wheels and tires.....The fronts are 275-35-18.

Will they fit on the 91 ZR1 Trying to decide how they would look if they fit on a 91Z.....Always like the shape of the Grand sport wheels....

[KILLSHOTS]

Your overall tire diameter on the 19s will be over 2" more, 28" vs. 25.7". Not good. Another problem will be the variation in wheel offset, which could be solved with spacers.

[Jagdpanzer]

325/30-R19 would be a better fit.

[Jagdpanzer]

You can do a side by side comparison here:

http://www.rimsntires.com/specspro.jsp

[32valvesftw]

315 is the width of the tire in mm, 35 is the aspect ration, so the rubber height is 35% of the width, 17 is the diameter in inches. As we never completely adapted the metric system some conversion is required. Take 315 and divide by 25.4 thats the width in inches, multiply that by 0.35, then double it, and add 17. Thats the diameter of the tire minus compression (usually neglible) if you put on a taller tire, it has the same effect as reducing the gear ratio, if you go smaller its like raising the gear ratio.

[Hib Halverson]

If it where me, unless I needed more clearance for bigger brakes, I'd never put 19s or 20s on a C4.

The reason is the tires have much shorter sidewalls. Such low profile tires noticeably increase harshness and C4s are bad enough already in that respect.

There is also the height issue but that can be fixed with 3.73 or 4.10 gears.

[Vette73]

Originally Posted by Hib Halverson

If it where me, unless I needed more clearance for bigger brakes, I'd never put 19s or 20s on a C4.

The reason is the tires have much shorter sidewalls. Such low profile tires noticeably increase harshness and C4s are bad enough already in that respect.

There is also the height issue but that can be fixed with 3.73 or 4.10 gears.

I agree with the harsh ride aspect....I was just considering the Grand sport wheels I saw but I do like my sawblades on the ZR-1 and mine are almost perfect....