My G37xS sedan has the factory 18 inch oem wheels that came with it. I'd like to replace the Dunlop tires that came the car with better performance tires. Tire Rack has the new Michelin Pilot Super Sport tires in 245/45x18, a size that is an almost perfect match to the oem tires, the sizing chart from Mich. shows a minimum 7 in. width to I believe a 8 1/2 in. wheel needed to mount these tires on. My oem 18s are 7 1/2 inches wide so it seems these tire will fit without any problems. My question is has anyone tried a size upgrade like this on their GxS sedan without any problems and being the wheels aren't as wide as what most people upgrade the wheels to (81/2 and 91/2 inch) would I still feel an improvement in handling and grip. Any thoughts on this change are appreciated. Oh, and of course I'll be buying a dedicated set of winter wheels and snows from Tire Rack for the nasty time of the year we get here in New Jersey. Thanks for the help.

 

I have stock 18's as well. 225/50/18 up front (7.5 width) and 245/45/18 in back (8.5 width) I am pretty sure you can run the 245/45/18 on the 7.5 just fine. Call Tire Rack, they should confirm that.

Personally, I will be changing to Vossen CV1's in matte black, 20x9 all around as soon as she's paid for.

 

[QUOTE=MACS;3107792]I have stock 18's as well. 225/50/18 up front (7.5 width) and 245/45/18 in back (8.5 width) I am pretty sure you can run the 245/45/18 on the 7.5 just fine. Call Tire Rack, they should confirm that.

Personally, I will be changing to Vossen CV1's in matte black, 20x9 all around as soon as she's paid for.[/QU

Thanks for the advise MACS, I will check with Tire Rack just to be sure.

 

I know you want to go bigger but why not get the Michelin in the 225/50-18 which is the correct tire for your rims.

Keep in mind
- you don't gain a lot of contact patch when you retain the same rim size but go up a size. you may only get half of the printed width increase.

- the narrower tire is less wind drag on the highway

- the 225 is lighter

- the 225 is over $100 cheaper per tire (tirerack)

- a properly sized tire is more responsive

 

^ I agree or you could try 235? 245 on a 7.5 might not look too good.

 

I think a lot of people want to go for the 245 setup all around because there are like 15+ more tires to choose from including the amazing Conti DWS's - All I all, I think the 245's on the front will look like steam rollers to some extent :P