[mhauser2]

search wasn't working for me, apologies in advance

what is the widest tire front and rear you can go on the stock 2018 SS rims?

i have seen 295/35-20 rear and 255/40-20 front

[enzia35]

Safest is 255/40 and 285/35. People have run 305/30 on the rear.

[Msquared]

What you can fit and what you should fit are two different things. For example, you can fit a 305/30/20 on 9.5 wheel, but that is outside the rim width recommendations for that tire. You can find those rim widths on lists of tire specs, and you should follow them.

[Billabongi]

Originally Posted by enzia35

Safest is 255/40 and 285/35. People have run 305/30 on the rear.

How far is the speedo off in the 255/285 setup?

[VinnAY]

Any reputable shop won't put a 305 on a 9.5" wheel, too, with that width on a narrow wheel you're not getting the tread footprint you would on a properly sized rim any way.

[arpad_m]

Originally Posted by Billabongi

How far is the speedo off in the 255/285 setup?

1.1% (when speedo shows 60, real speed is ~60.6)

[arpad_m]

Originally Posted by mhauser2

search wasn't working for me, apologies in advance

what is the widest tire front and rear you can go on the stock 2018 SS rims?

i have seen 295/35-20 rear and 255/40-20 front

I ran 255/40/20 and 285/35/20 with the stock wheels and that's as far as I would want to go.

(With a narrower profile tire, as not all tires have the same physical shape even in identical sizes, one might go up to 265 and 295, respectively, but at that point diminishing returns kick in, plus the front tire may start rubbing against the spring perch or at least the outermost nipple, there isn't too much clearance. Not worth it IMO, if you want wider tires, you need to surrender to the need for matching wheels.)