I'm at the point where I need to either replace the stock 16" tires, or upgrade and go with a set of new wheels and tires. I want to know what is the biggest tire/wheel combo that will fit on my 99 STS. I'd like to run 22s but that may be pushing it. Realistically, I like to slap on a pair of 245/40/20s up front and 275/35/20s out back.

Anyone running rubber that big in the rear?

Kale

Do you have the power for that rubber? If not, why waste the money. . .

Bone stock it has almost 300 lb/ft of torque and a 3.71 final drive ratio to boot. My Mark will bark the 20s at a WOT 1-2 shift, and it has less torque and a 3.08 final drive ratio.

So yes, I do have the power for all that rubber. :)

Kale

Will you take a look into the thread W.C. What State Are You In. Please do your sign in. So, we have you and the state you are from!

Im upgrading to 22's from 20's since i saw them on a 2002 sts in person. I didnt believe the guy at first and he rode up in his sts and it was true, he has 22'' dub C.R.E.A.M. rims with diamonds it them, total cost for them were $20,000, Insane right! although the car looked sick and he snipped a little from the inside and thats it. the camber kit thats on the sts is perfect for this upgrade, even if you were to go with 20's.

if you dont have the same tires on front and back:
1. it will look weird, and
2. it will mess with the ABS system.

22's should be fine if u got tha bread for it