: Different size tires on 2005 STS



grundynative
07-07-10, 08:45 PM
I own a 2005 STS rear wheel drive. I want to know what "Einstein" at GM thought of having two different size tires on this vehicle. I can't even rotate them like I'm supposed to. I want to know why this was done and can I put the same size tires that are on the front, on the rear. All of the rims are 17" so I don't really see a problem. The same size tires all around shouldn't have any effect on the handling, ride or steering.

How about a answer from a knowledgeble person.

grundynative

dkozloski
07-07-10, 08:55 PM
I own a 2005 STS rear wheel drive. I want to know what "Einstein" at GM thought of having two different size tires on this vehicle. I can't even rotate them like I'm supposed to. I want to know why this was done and can I put the same size tires that are on the front, on the rear. All of the rims are 17" so I don't really see a problem. The same size tires all around shouldn't have any effect on the handling, ride or steering.

How about a answer from a knowledgeble person.

grundynative
Many owners have installed the same size tires all the way around. Some report no trouble and some report many TC/ABS codes and messages. In addition, the rear rims are wider than the fronts so it may look a little strange to a discerning individual.

I use the same size winter tires all around and live with the strange look of the rears.

You'll find staggered tire sizes on many of the newer cars.

MacMuse
07-08-10, 04:31 PM
While the rims are 17", they *may* be two different widths. The normal factory setup puts 17x8 rims on the back, and 17x7.5 on the front. You can still put the same size tire on all, and even do the traditional rotation. But, handling may be altered slightly with the wider rims up front.

EDIT: whoops, missed DK's rim reference in his reply. Never mind.

Caroutisine
07-08-10, 10:22 PM
I ran the front sizes for 2 winters on all 4 corners with no problem at all. I did keep the rims from front to rear in the same locations though.

EChas3
07-08-10, 10:38 PM
With the 18's you get your choice:

Opt for quiet & ride = 235/50
Opt for handling & feel = 255/45

kschwed
07-09-10, 01:07 PM
I have the Yokohama Advan s.4 235/50R-17 all around with no problems.

Subsailor613
07-09-10, 02:16 PM
I had to put larger (Wider) tires on the rear, as I would go around a corner,
and with just a little gas, it would spin the tires,So I went wider on the rear
and I am Happy with the traction I have NOW ! :welcome: ;)
At least this is the way I drive, you may NOT drive as hard as I do ! :yup:

amgqmp1
07-10-10, 12:33 PM
I had to put larger (Wider) tires on the rear, as I would go around a corner,
and with just a little gas, it would spin the tires,So I went wider on the rear
and I am Happy with the traction I have NOW ! :welcome: ;)
At least this is the way I drive, you may NOT drive as hard as I do ! :yup:

I plan to do the same thing when my tires are ready to change. The 235/50/17 setup isn't one I'm fond of. I drive like an old man (mostly), and I find the rears cut loose far too easily.

kschwed
07-10-10, 08:12 PM
I plan to do the same thing when my tires are ready to change. The 235/50/17 setup isn't one I'm fond of. I drive like an old man (mostly), and I find the rears cut loose far too easily.

Never had a problem here and I have somewhat of a lead foot.

MacMuse
07-11-10, 09:28 PM
Always wondered how to quantify 'lead foot' v. 'like and old man'.

I recently ran a little mileage experiment over several full tanks of gas with my normal daily driving patterns. I discovered if I don't let RPMs ever exceed 2000 - especially from dead starts - my mileage "skyrockets" back up to the EPA ratings for my car.

Now, it takes a lot of patience to let every Tom, Dick, and minivan blow you away at every light - but it really works. I also discovered that seems to be a key RPM level to keep the back tires engaged in the rain, a severe problem I had the first 6 months I had this car.

So, am I officially an old man driver when I go this route?

Ya know, I probably don't want to know the answer to that one.

EChas3
07-11-10, 10:51 PM
Figure each MPG you save is a gallon per tank. Sometimes a gentle cruise is fun; but my STS shines when pushed harder. Gas is cheap!