Hey Tyson, I'm trying to get Michelin PS4S's for our car but they only come in 245/40 for 18" wheels. I like the ride comfort of the 18's, do you know if 8.5" wheels will be too wide for our cars? Ideally I'll just pick up a pair of 18x8.5's and use them with the PS4S's for summer and toss on the stock ones for winter until they wear down, then get winter tires. If 8.5" isn't too wide for the car, any idea what offset I'd want?Offset would really depend on the width of the wheel, if you want to step it up to a 8-8.5 inch for more of a contact patch that will change, I have always used Online Wheel and Tyre Fitment Calculator. Offset, Tyre Stretch and Speedo Error | Will They Fit along with www.tyrestretch.com to calculate proper fitment for customers, as well as my car, once you get it figured out and have taken proper measurements from your car, both inside and out, it is pretty straight forward, if anyone ever needs a hand please let me know and I will do my best to get you sorted!
Air won't add weight.I weighed all 4 wheels as I put them in storage. 49.6, 48.7, 48.5, 48.7. Wheels only had 600 miles on them. The 49.6 was a front and I had just driven so perhaps it had a higher pressure which added weight?