: What is largest tire size you have put on 07-09 STS?



jimzilla
07-03-09, 07:46 AM
I am looking to replace my trires on an 08 STS with 18 inch wheels. My favorite Goodyear tires are eliminating 235/50 18 and I am wondering whether 255/50 18s will fit in front. Has any one tried with good success?

EChas3
07-03-09, 01:49 PM
P255/45R18 fit on the front of my 2006 just fine. Your 255/50R18's would be 3.57% too big. Your speedometer would be 3.706% low. Many people would consider this varience from stock to be dangerous and/or potentially damaging.

265/40R18 would be 2.56% too small. 275/35R18 would be 5.41% too big and I'm pretty sure they would rub.

Play around with this:
http://www.1010tires.com/TireSizeCalculator.asp

Good Luck!

jimzilla
07-03-09, 05:00 PM
Thank you Echas. To be clear about the 255/45-18s fitting your 06 STS, I assume you mean you have them on and have have driven around on them for some miles? Any problems at all? Do you drive in city? rural? potholes etc?Let me know when you get a chance. Thanks in advance.

WillySTS
07-03-09, 05:21 PM
Thank you Echas. To be clear about the 255/45-18s fitting your 06 STS, I assume you mean you have them on and have have driven around on them for some miles? Any problems at all? Do you drive in city? rural? potholes etc?Let me know when you get a chance. Thanks in advance.

If I may intrude...255/45X18 is the OEM size for the front tires on the STS-V and the rears are bigger 275/40X19...so, yes,...they fit.

EChas3
07-03-09, 05:40 PM
^^^^^ Yep!


Thank you Echas. To be clear about the 255/45-18s fitting your 06 STS, I assume you mean you have them on and have have driven around on them for some miles? Any problems at all? Do you drive in city? rural? potholes etc?Let me know when you get a chance. Thanks in advance.

The DPO & his dealer had rotated the P235/50R18 - P255/45R18 every 15,000 miles. When I got it, the tires were on the wrong ends with no adverse effects (other than the blushes from the selling dealer).

I do wonder how big one could go with the ZF Steering. It seems to have a quicker steering ratio but I don't know if the turning radius changes. :hmm:

Vince59
07-04-09, 12:01 AM
Thank you Echas. To be clear about the 255/45-18s fitting your 06 STS, I assume you mean you have them on and have have driven around on them for some miles? Any problems at all? Do you drive in city? rural? potholes etc?Let me know when you get a chance. Thanks in advance.

Hey Jim got your PM, but unfortumately the system won't let me send PM's.

Anyhow the 255/50/17's I put on my car give added protection to the wheel, and the tires also improved the ride and handling, the stock Michelins IMO were horrible.