Okay, perhaps I'm a little confused on this since this is my first time buying custom wheels. Anyways, to keep things short, I plan on buying a set of 4 TSW Mondello wheels 18x8 with an offset of 20+ (I hope that's ok...). The reason I'm going 18x8 front/back is so that it is the same spec as the OEM 18 inch wheels (except for the 10mm difference in offset).

Anyways, I have the stock 17 inchers on which have 225/50-17 in the front and 235/50-17 in the back. The 18 inchers are 225/45-18 front and 245/45-18 in the back. So here's my question. Discounttire direct says that two tire sizes that fit this size of wheel (they also give the same sizes when you want to plus size from the stock 17 inch setup) is 225/45-18 in the front and 275/40R18 in the rear.

I compared the different size rear tires using this tire size calculator: http://www.1010tires.com/TireSizeCal...?action=submit , and found that the 275/40-18 tires have a closer diameter to the original 17's in the rear. Does that mean that it's a better choice in the rear compared to the actual tire size Infiniti uses for 18 inch wheels?

Any help would be appreciated....

 

275/40/18's won't work on an 8" wide wheel, so if you want to run this size, step up to a 9" wheel at a minimum

 

That's what I was thinking. Don't know why Discount tire direct lists that as the only other tire size that fits a 18x8 wheel. Seems like they aren't very reliable....

 

You are right. I talked to the folks at Discount Tire and they said that the 275/40-18 will be good for an 18x9 wheel in the back.

Think that would be better than running 18X8 front and back with the stock staggered tire setup?

 

Yes, an 18x9 in the rear would be a better size, most people run at least a 8.5F/9.5R setup here with good results, and a 245F/275R tire