: 2006 sts Tire Question



bbjorklund99
04-15-11, 01:00 AM
Hello All,

I am new to this board. I just purchased a used 2006 STS V6 with about 45,000 miles on it. It was a 1 owner and appears to be a really nice car. I am a first time Cadillac owner who just upgraded from a 02 Chrysler 300m and love pretty much everything about this car.

My question has to do with the tires that are currently on the car. The previous owner replaced the original tires at about 34,000 according to a slip I found in the glove box. He put on Dunlop SP Sport Signature tires which appear to be decent tires. The problem is that he put 235/50r-17's on all 4 wheels and the originals were 235/50r-17 in the front and 255/45r-17 in the back. The rims on the front are 17x7.5 and the rims on the back are 17x8. The dealer I purchase the car from rotated the tires before I purchased the car and they put the wider rims are on the front. I will move them to the back where they belong this weekend. The real question is based on the fact that GM designed the car to have different size tires on the front and the back. Will running the car with the same size tires on the front and back with the different size wheels cause me handling or other problems?

I have never had a car that is this high tech so I am looking for advise from somebody that knows more about these cars than I.

Thanks,

Brad

KRSTS
04-15-11, 07:43 AM
I also had to replace my original OEM michelins at 34,000m. I chose the Yokohama Avid Envigors, but the Dunlop SP Sport Signatures were my second choice - an excellent tire from my research. If I were you I would replace the 17X8 wheels with 17X7.5 wheels and remount the tires. You can find the wheels on ebay for about $150 each and then sell the 17X8s. I don't know why one would need a staggered setup on a 2006 V6. I don't know if having 235-50-17s mounted on 17x8 rims will hurt anything, but having the same size on all 4 wheels sure helps in tire rotation. Just my opinion. BTW enjoy your new ride, I sure enjoy mine.

bbjorklund99
04-15-11, 09:32 AM
Thanks for the response! Does anybody know why they put wider wheels and tires on the back? Does it have to do with the alignment of the tracking so that there is improved traction in the rain and snow or is there another reason?

Brad

C&C
04-15-11, 11:36 AM
Even though I believe the acronmym for STS is Seville Touring Sedan I believe at one time is was for Sport Touring Sedan. With this said, and the aim of the engineers to produce a 'state of the art' sedan (at the time), every little bit of performance was gleaned out of the suspension. In real terms, the differences in driveability were neglible, but if you looked at handling statistic numbers, I assume the staggered setup was a smidge better (at the proving grounds). As latter presented, even Cadillac, produced later STS's with same sized wheel/tires packages so at least you have options on how your Cadillac's tires are shod.

bbjorklund99
04-15-11, 12:09 PM
Thanks for the response. For what I am going to do with the car it probably isn't going to make a difference although it probably makes sense for me to put the wider wheels on the back as they were from the factory. It may make sense to get a pair of 17x 7.5 wheels from Ebay to replace the 17x8 wheels that are currently on the car. At that point I can put the wheels anywhere on the car without causing any concerns.

Thanks,

Brad

EChas3
04-15-11, 10:30 PM
Don't sweat it. a half-inch of wheel width isn't material.

Frikiton
04-16-11, 04:52 AM
I also had to replace my original OEM michelins at 34,000m. I chose the Yokohama Avid Envigors, but the Dunlop SP Sport Signatures were my second choice - an excellent tire from my research. If I were you I would replace the 17X8 wheels with 17X7.5 wheels and remount the tires. You can find the wheels on ebay for about $150 each and then sell the 17X8s. I don't know why one would need a staggered setup on a 2006 V6. I don't know if having 235-50-17s mounted on 17x8 rims will hurt anything, but having the same size on all 4 wheels sure helps in tire rotation. Just my opinion. BTW enjoy your new ride, I sure enjoy mine.
Yes same size helps for rotation, but his is probably like mine (1SC = Luxury Performance pkg) which comes with 235/50 front and 255/45 rear factory.

But from what I read on this forum the wider tire on the rear might be more of a look than anything. Even though if you have the $$ i would keep it factory.


Thanks for the response! Does anybody know why they put wider wheels and tires on the back? Does it have to do with the alignment of the tracking so that there is improved traction in the rain and snow or is there another reason?
Brad

I don't know if it has improved for me or not, but now when I do take fast turns or curves I feel it more. If I had a choice to keep it OEM I would. But others will tell you otherwise. I put 235/50R18 all four because I found $500 savings on a tire deal and couldn't give it up. But hey let me know what you decide love to hear your opinion.

bbjorklund99
04-16-11, 09:27 AM
Thanks for the response. I haven't decided for sure what I will do but I will probably put the wide ones on the back. I don't know if i will notice a big difference one way or the other based on the kind of driving I do. I do however like the looks of the wider tires in the back. I reminds me of my youth where guys would jack up the back of their cars and put wider ones on the back. I trust that the engineers at Cadillac did it for a reason so I will probably put it back to original. I have a local tire dealer that treats me right and he will probably give me a good trade-in on the tires I have. I definitely will be moving the wide rims from the front to the back where they belong. I like the looks of some of the 18" wheels but have heard mixed reviews for the larger rims on the V6 model. Have you noticed any negatives from changing to the 18" wheels and tires? If I keep the car long term I can always upgrade the wheels, grill, etc. I plan on having some fun with this gem. My first purchases will be lockpick and an updated Nav disk. I cannot believe how irritating the navigation system is on these cars. It is one thing to lock out the DVD while moving but the GPS and Bluetooth you may as well not even have it.

Brad

rnkath08
04-16-11, 03:38 PM
I kept mine OEM and went with Continental DWS staggered...love them so far!

z06bigbird
04-17-11, 10:02 PM
Purpose of staggered wheels/tires:

1. owners cannot rotate tires; tire, then, will wear prematurely.
2. result: more tire sales.

Tips on buying and selling wheels.

Q. What are hardest parts to sell on any car?
A. Doors and wheels.

If you look on craigslist, you will regularly locate Cadillac wheels for as low as $50 to $75. (I just purchased 4 Escalade 18" polished alum wheels and new tires for $550.) New car take-offs; no brake dust. No problems.

Last year, I purchased a nice set (4) of STS polished alum wheels and new Michelins for $150 total. Not hot either, as there was a cop with me during the purchase.

Personally, I would not buy refurbished wheels cause you don't know the extent of previous damage. (My life is worth more than a few hundred $$.)

z06bigbird
04-17-11, 10:05 PM
Don't sweat it. a half-inch of wheel width isn't material.

Just be careful that the widest part of new tire on the new rim extends out past the edge of the rim. If not, you wife just might leave the edge of the rim on the curb. We all know how wives are!! Widest part of new tires should extend out perhaps 1/2 inch past rim edge.

onlyuscars
04-17-11, 10:37 PM
Brad,

I'll swap you my 7.5 front wheels for your 8 inch rears. I have polished aluminum. Interested?

My skin in the game is new rear snow tires on your 8 inchers, moving my current rears up front and discarding the bald fronts. You would have the proper size wheel for the tire. I know that for rain, snow, and fuel economy 7.5 is better all around, but I like more rubber. If you are in the Northeast we could do a swap meet.

As far as upgrading to 18's...I went to 20's