I am considering gettin 18" rims...my tl isnt lowered and i was wondering what kind of offset i would need and also wut dimension for tires i should get...i dont kno much and was wondering what size tires i should get if i want low-profile tires...thanx...

 

I'm running 225/40/18 tires on an 18x8 wheel with a +45 offset and lowered about two inches. So far, no rubbing. When I had an 18x8.5 wheel with +45 offset, I was rubbing in the rear even when the car wasn't lowered.

 

i wanna get 18x7.5's..once again my car is NOT lowered...what should my offset be then?...also..the lower the first number in say....225/45/18....the lower the profile?.....thanx

 

+45 or greater seems to work around here.

As for your example (225/45/18), 225 is the tread width in mm of the tire, sidewall is 101.25 mm (225mm * 45%), fits on an 18 inch wheel.