95viper

OK, I decided to start another thread because everything in my other one was about getting a 35 series on a 20" rim. Now that I have given up on that idea I am moving to 19's.

245/40/19 diameter 26.7 and 285/35/19 diameter 26.9 seems perfect. Fills up the wheel gap nicely with no lowering. Lots of sidewall to prevent bent rims.

So you didn't think I could complete a post without drama, right? Now I would like to know what the ultimate offsets are with the sizes above.

I took a stings today and taped them to the fenders with weights. I have OEM rims et 25 and et29 but I have wider tires than OEM. I have 255/40/18 and 285/35/18. So lets start with fronts.





Front driver side
Widest part of tire to string 2mm
Wheel to string 7mm

Front passenger side
Widest part of tire to string 5mm
Wheel to string 10mm

I can assume that my garage floor is not level but I didn't think of backing the car into the garage to validate. I will probably do that tomorrow. Assume that is true and level measurement would be 3.5mm tire and 8.5mm wheel to string.

Rear driver side
Tire to string 6mm
Wheel to string 16mm

Rear passenger side
Tire to string 11mm
Wheel to string 21mm

Again, assuming floor is unlevel...a level measurement is 8.5mm tire and 18.5mm wheel to string.

95viper

Recap - my car 07 CLS550 assuming that I validate unlevel floor...

Front 3.5mm tire to outside of fender and 8.5mm wheel to outside of fender
*note that this is a 255 tire and I will be running a 245.

Back 8.5mm tire to outside of fender and 18.5mm wheel to outside of fender
*this is the same width that I will be running.

95viper

Before I make any other assumptions I am going to re-measure with the car facing the opposite direction. I will report back.

95viper

Drove car around block and backed in garage. Passenger side measurements stayed the same but driver side different. Tire pressures all spot on. The only thing that I can guess is that I was jacking up the driver side and didn't drive car afterwards so maybe that did something.

Driver front to fender
tire 5, wheel 10

Pass front to fender
tire 6, wheel 11

Driver rear to fender
tire 9, wheel 19

Pass rear to fender
tire 11, wheel 21

Again, this is OEM 18x8.5 and 18x9.5 wheels with wider 255 / 285 tires

95viper

I guess I am mostly surprised about the front tires. They are Pilot Sport 3 in 255/40/18. I would expect much more tire on a 8.5 wheel. I have a 10mm difference in the rear but only a 5mm in front. I don't get that. OEM was 245 so that would sit flush with wheel?

95viper

I think Michelin had a batch of skinny 255 tires because their website says these should be 10.2" wide. No way are mine on a 8.5" wheel. I checked air pressure again too.