Tire recommendation

... or the front size if you prefer a quieter, more compliant ride.

You don't say what model Michelin's but most turn to rocks sooner than they should (IMHO). We are real happy with our Conti's; DWS & DW.

255/45R18's don't rub on the front.

Experienced member engineers claim performance considerations led Cadillac to equip the higher trim level STS's with 17" & 18" staggered setups. Others say it was a marketing decision.

Either way, IMHO most of the Michelins are over-rated.

The only OEM tires I ever re-fitted were the Goodyear Eagle GA's on my '93 Buick Roadmaster Limited.

They really suited that beast and 3 sets (minus the spare) took it most of the way to the moon; 200,000 miles! I cheaped out after that when my local guy convinced me to mount Firestones. They were OK but by that time the car was getting geriatric. I gave it to Bart Starr's Rawhide and made more on the tax deduction than I ever would've otherwise. (Now, it's the receipted proceeds.)