LS4 Performance - GXP Eating Tires- Same size front and back??

Is it just me or does anyone else have issue with their GXP eating tires?
I have a stock 07 GXP and the front tires will need replaced again after about 12K Miles. I maintain correct tire pressure and the car is in alignment.

I was told to just put the same size tire on the front and back of the car and start rotating the tires. I was told I would get alot better tire life. I am getting sick and tired of buying tires every 12K miles and am willing to sacrafice handling to save some green.

Has anyone had experience putting the same size tire all away around?

Will 255/45 18 fit on the back of this car with stock rims?

Or just put 225/50 18 up front?

Any ideas for improving tire life would be appreciated.

12k miles seems pretty excessive unless they are really soft tires, I would expect to get about 30-40k out of a set of fronts, and mabye more out of the rear ones.

And I don't know who told you to rotate them but that is not what I would do. The fronts are bigger for a reason, its because they support 64% of the weight of the car, and with that they are supposed to make the car handle better when pushed hard in the corners.

The rims up front are different size than the back obviously and no you cannot put a 255 tire on the rear 7" rims, but I have heard of people putting 235's all the way around. I personally would not do it though.

If you are putting 225's on the front though then yes you are going to eat them alive if you drive somewhat spirited, they are just not built to handle the weight and the constant stress that it puts on them.

I run falcon 275/40/18's anything else I usually wear out in one summmer. 225/40/18's on back. Also I did a realignment at gm and something about it needing reslotting and camber bolts.

Sell them and find some rims you like that are the same width and run same size tires. Bonnevile GXP rims, or run 4 front 18x8's all the way around.

i thought i heard somthing about not being able to rotate the gxp rims... different offset or somethin and maybe different lug nuts?

Stock GXP rims FRONTz 18" x 8" REARz 18" x 7"

No you can not rotate them as the rims are different sizes. My GXP chewed my tires up really bad as the car had a bad alignment from the factory.

The size difference has nothing to do with the weight of the car. The 5.3 V8 (aluminum) is actually lighter than the Iron-block 3.8 Supercharged GTP's V6. The tire size difference was done to make the car handle more neutral in the corners. GM took a BMW 545i and parked it in Pontiac's garage next to a GP and basically said, "make it handle more like this." Anyways, as stated before, the front and rear wheels are actually different sizes, so you can't just throw the same size tires on all 4 and let it ride. I mean I suppose you could try the 235's all around but ideally, you want to buy 4 matching wheels first.

I have a gxp. And I run one size of winter tires on all the rims. But only way to rotate the tires is to unmount and mount them. I do that every year when I put them on for the winter. I have 245/45/18 that I have been using. Next year I will be tryin 235/50\18 all around for winter tires

^^Best winter tire size ive found has been 225/55-18 I use blizzak ws-70s and they're beyond awesome in the snow...overall height of your wheel tire combo is what's most important in the snow...common misconception is that the sidewall height alone that makes a difference , but for example a 225/55-18 and a 225/45-20 would perform equally in the snow (the 20 is .1 inch taller but the point is clear)

Driving style would have a lot to do with why your tires are only lasting 12k...try getting an all season, they will last you longer...stickiest all season I've found is the Toyo Proxes 4 and they ride unbelievably smooth too even as 245/35-20s

[QUOTE=BlauGXP;16103943]The size difference has nothing to do with the weight of the car. QUOTE]

Dude read what you just wrote, you contradicted yourself even.

If you are putting bigger tires on the front of the car to make it handle more neutral around corners wouldn't that be because it weighs more in the front?

I swear come people argue things they know nothing about just for the sake of arguing.

http://www.caranddriver.com/reviews/pontiac-grand-prix-gxp-road-test

I just put 255/45/18 all around on my 06 SS and have no issues at all

255/45/18 on an 18X8 GXP wheel mounted on the rear will rub the fender lip unless you add negative camber. Let me rephrase, if you have four adults in the car with the 255 tires on the rear it will most likely rub the inner fender lip unless you add camber which will wear out the inner part of the tire worse than it seems to on the 235's. JME

I had 5 ADULTS in my car and I didnt rub once. Also I am running the correct alignment as well.

Well using cam bolts I damn near zeroed out the camber in the rear wheels, less than oe specs, and mine rubbed. Prolly my fault for not allowing enough camber.