bones700

Just purchased a used 08 grand prix gxp. I noticed that it has different size tire on the front from the back. Could i run the same size on the rear that are on the front? thanks for the info. in advance.

Taz34SS

iTrader: (2)

I do not believe you can, but what you could do is buy the same size rims for the front that are on the back and that should work.

There are alot of GXP guys on this board, so I am sure they will comeup with something aswell, but I Think that would be your best best.

TiredGXP

iTrader: (2)

There's a reason GM put bigger tires on the front - to reduce understeer. If you put the bigger tires on the rear (or smaller on the front), you'll unbalance the suspension and make understeer worse than it already is.

But what the hell, the Montes and Impalas don't have the staggered tires.

Taz34SS

iTrader: (2)

I was wondering if that would make a difference with the GXP... THanks for the input on that, I didnt think about those things.

MonteSS8707

iTrader: (4)

On the GXP's the frt wheels are 8 in" wide rears are 7 in" wide. I dunno if it was all done to reduce understeer. Monte and Imps all have 18 x 7's all the way around stock. They prob did it like old drag, cars only we're frt wheel drive. I would just get 18 x 8 for the rear. When I have to get new tires for my MCSS I'm gonna go with 255/45/18 all the way around. But I got 18 x 8.5 wheels though. Typically the wider the tire the more effective contact point with the road= more traction.

Taz34SS

iTrader: (2)

Is there anything special we would have to do to make them work on the monte, the 255/45/18 size?

bones700

Thanks for the info guys. On another note,how hard would it be to put a spare in the trunk? Will a 18" wheel and tire fit , or is it designed for the standard 16" wheel and tire. This car is the wifes daily driver,so im just trying to head offa problem. We also have a solstice gxp,and that car doesnt have a spare either. No place to put one. Thanks again.

BuffaloSS

iTrader: (3)

Bones...there is a (Cadillac) spare tire that fits over the brakes and fits, somewhat, in the trunk. There's a big post about it on ClubGP, if you REALLY want to venture into that abyss

MonteSS8707

iTrader: (4)

Bones I doubt you'll get an 18 x 7 in" wheel in the trunk space provided for the spare. You could just set one in the trunk if you really wanted but i don't see it fitting where the spare is.

Taz, I would say to go to an aftermarket wheel at least 8 in" or wider if you wanna run 255/45/18 tires on your monte. I'm sure you can fit that tire on the stock 7 in" wide wheel but it will look like ****( sides bulging out) and might not be the safest thing. Too wide of a tire on too skinny of a wheel. I think suggested wheel size for 255/45/18 tires are 8-9.5 in" wide wheel. Like I said you physically can do it, but I wouldn't recommend it on factory wheels or wheels under 8 in' width. Look on tirerack for aftermarket wheels, they have quite a few and some great deals on them. I got mine for a good deal on clearance. Thats what I'd do. I'm gonna go the 255/45/18 route when my shitty goodyear eagles finally get bald. Also Taz I'm gonna post a rocker thread with some pics soon. Look at my updated sig. Got em on!

dcrews

iTrader: (3)

WOO someone who tried the Summit rockers! I can't wait for your thread!

EmersonHart13

iTrader: (3)

Club GP does have a nice write up on the spare tire and the rationale on why they set the car up like that.

Seriously if you want all the same size why not just buy the Impala? :-)

randallgxp

My girlfriend bought a 07 Grand Prix GXP and we are due for the first set of tires. She drives it back and forth to work and is a daily driver. What is the deal on the tires? I am ASA late model crew chief and I understand why they are different because of understeer and better handling. I would like to put four tires on it that are the same size. I don't worry if it takes a little of the handling away. We live in WI and it is driven in winter. What size and tire should I put on? It's not like I'm taking it to Road America to take a couple of laps.

jderou_GXP

255's front and rear works just fine.

GXP25

iTrader: (3)

And if you really want them to last, buy a camber kit for the rears.

Panther427

I put 245/45 18 hankook tires on my GXP in the winter.. and then the stocks back on in the summer all on the factory wheels.

Nick_Nasty's_GXP

iTrader: (4)

It's the Caddy DTS. Not sure what year, but I was thinking about getting a spare in my GXP also, seeing how I have VERY bad luck with tires