I'm looking to increase tire size on a 1998 Volvo C70.


Currently, the tires are the stock Michelin Pilot Super Sport 225/45 ZR 17 (94Y).

I'd like to increase the width and the height a little bit and I was wondering if anyone had any insight on the limits the wheel well can take without rubbing issues or gross instrument errors.

Here are the replacement tire sizes I'm interested in:


235/50R17 96Y Michelin Pilot Sport
245/40R17 91Y Michelin Pilot Sport A/S 3
235/45R17 97Y Michelin Pilot Super Sport

 

Welcome & happy modifying your Ride !

 

Cheers! Thanks!

 

Welcome to the forum

Moved your post to your cars section.

 

Plus 1 in aspect and ratio shouldn't effect any components but give you a wider tread and a taller tire.

 

Do you think there's any significant chance of unwanted rubbing between the slightly larger tire and the wheelwell, suspension, etc.?

 

the fit will also depend on your rim's offset and width. You should see a stamping like ET43 - the 43 refers to the mm of offset the rim's center has from the hub but assuming you are keeping the existing rims and go from 225/45-17 to 245/40-17, you will add roughly .5 to .7 inches to the tire's cross section width - so take a close look at the existing gaps to see if you have space between the tire and the strut tower and then crank the wheel all the way left and right. If you go to a wider wheel the width would be even more. Keep in mind the clearance will change as the spring compresses. I'd say it'd be close. As to the instrument errors, going from 225/45-17 to 245/40-17 is a proper upgrade - the circumference difference is less than 1%.

 

Thanks so much for the tip about checking the ET43 stamping. I'm wondering now under what conditions to measure the tolerances. Does the car need to be over a grease pit? Can the measurements be done when the car is on a normal jack? How do people normally go about taking a look at the tolerances?

 

Don't exceed the +1 +1 rule and you won't have to worry about rubbing anything ! Good luck.