View Full Version : What tires To Replace Michelins on 06 STS?

Greg Gore
10-05-07, 01:07 PM
Hi Folks:

I am experiencing extremely noisy Michelin Pilot tires on an 06 STS which I guess is a common complaint and would like to replace them with suitable GoodYear ZR rated replacements. The only thing I can find available in my sizes is the F1 GS-D3 which has a dual diagonal high performance tread pattern. The F1 GS-D3 reportedly has extremely good performance on either wet or dry pavement but not so good in winter conditions. GoodYear has a newly released ZR rated F1 All-Season tire which looks better for year round but is not available yet in one of the two sizes I need.

Car has 235/50 ZR17 and 255/45 ZR17 Michelins now, What are my options to put a good tire on this car?

Thanks in advance!

Curious George
10-05-07, 04:28 PM
This'll be costly, but... Get the factory 18x8.5 wheels (or equivalent--the Cadillac accessory wheels look very nice). Then buy 255/45R18 99Y tires for all four corners. The 1SG+PHP cars (Premium Luxury Performance Group + Performance Handling Package were--are--so equipped. Michelin Pilot Sport 2 or Pirelli P-Zero (NOT Rosso and NOT Nero) have gotten good reviews. I replaced my OE Michelin Pilot Sports with the Goodyear Eagle F1 GS D3s. They perform and ride better than the OE tires. The PS2s and P-Zeros have tested better recently (Tire Rack and Consumer Reports November issue.) These are UHP Summer tires, and afford excellent performance, wet or dry. Performance degrades in really cold weather, and they are USELESS on snow or ice. If you live where you encounter snow or ice, either buy a set of Winter tires for your snow season or buy UHP All-Season tires.

PS: Fitting 255/45 tires may throw off your speedometer and odometer--their rolling diameter is larger that your OE tires. Perhaps you could fit 255/40 tires to avoid this. Your tire dealer can compare rolling diameters for you.

10-05-07, 07:22 PM
I have the 1SG and put the new Eagle F1 all season on about 1500 miles ago, but I was looking for something that would work in snow also. I might have to get full all out snows, but I figured I would try them. They have great grip but are not the quietest tires due to that grip. I pick up every little rock, acorns and throw them when I get up to speed. I have run Toyo, Conti's, Kuhmo's, but I think I like the F1 all seasons the best. If I did not have to worry about snow, I would do the F1 G3 summers in a heartbeat. I wold get the XL load rating ones.

Greg Gore
10-08-07, 09:09 AM
If it wasn't for the poor snow traction I would get the GoodYear F1 GS-D3's. The STS is my wife's car and she travels about 25 miles one way to work and the concern would be about her trying to get home safely with a wintery mix on the roads. Maybe there is not a good all season GoodYear tire for this car right now but what about other manufacturers? I would like to keep the original 17" wheels on the car and am just looking for recommendations from other owners who found something to replace the OEM Michelins which are noisy to the point of being annoying. We're really ready to pull the Michelins off even though they have a lot of tire life remaining.

10-08-07, 10:03 AM
This is what I got.

Greg Gore
10-08-07, 10:28 AM
That's the tire I originally wanted but GoodYear has not made it available yet in 255/45 ZR17 for the rears. Looks like you went with the 275/40. How much of a change is it to go with 275/40 ZR17 on the rear on the stock rims?

10-08-07, 11:35 AM
I will be interested to see if anyone has a big change in road noise when they change tires. My STS with the original Michelin Pilot tires is noiser than my Silverado truck on certain course road surfaces. I just think it is the unibody construction without any real rubber isolation in the suspension.

10-08-07, 11:41 AM
I have the 18inch wheels with the fronts & rears having 2 different sizes. I used tire rack to get the prices and sizes and had a local tire shop match the price. Not a lot of tires in that size on the rack. If it was me and the car was just RWD. I think I would try 4 of the dunlop winter D3's and run them year round or until something else comes along. Somebody with a DTS wrote a review about them and everybody seems to like them. They might not last as long, but you never will kick your self for having traction..

Greg Gore
10-08-07, 12:34 PM
I gotta do something... more than just tread noise on the pavement. Think I have a problem with the belts too as its loud and noisey with every revolution of the tires on smooth pavement... loud constant wump wump wump. I believe the Caddy is capable of much better than that! Heard there are a lot of other complaints on the OEM Michelin Pilots. Will look at the Dunlop Winter G3's. Am looking for good all weather traction for wife using the car in daily commute.


10-08-07, 03:23 PM
"Car has 235/50 ZR17 and 255/45 ZR17 Michelins now" This is what my car came with as well..I haven't started searching much for actual tire sizes etc. but I had planned on putting 4 255/45/17's on and doing away with the different front/rear sizes. Unless someone says otherwise I don't think it should be a problem. For tires, the F1 all seasons look good as well as the Kumho's ecsta's (I think) seem like a good replacement.

"Looks like you went with the 275/40. How much of a change is it to go with 275/40 ZR17 on the rear on the stock rims?" I'd like the know this as well? If I'm thinking right, the 275 is a much wider but lower profile tire than the OEM correct?

10-08-07, 05:49 PM
I don't know if your speedo will need to be reworked by the dealer for the new tire size, but I stayed with the stock sizes on the stock 18 inch rims for that reason. Plus, you have to figure that there must be a performance reason that Caddy did that ?. But after replacing the cabin filter, it looks like the factory can make mistakes.