I have an 03 GT with stock bullitt rims, i belive they are 17x8 with 245/45 tires. I want to get some wider rear tires and was thinking mabe a larger rear rim. I did some research with this calculator http://www.rimsntires.com/rt_specs.jsp and found out that there are no tire combos that would be the same size as 245/45/17's on a 18 inch rim. Should i just stick with 17s rear?

for example

my tire height with the 245/45/17s is 25.7 inches.

for a 305/30/18 the tire height is 25.2 (305 35 18 is farther from 25.7)

for a 305/35/17 the tire height is 25.4 (305 40 17 is also farther from 25.7 than this size)

Do the tire heights need to be exactly the same for the ABS to not malfunction or have any problems? What is an acceptable staggered wheel combo with a 245/45/17 front. I want a wide rear rim and hopefully 305 or so rear tire. Is this just not recommended?

 

Differnet tire sizes won't be the end of the world. Jazzer says you shouldn't go more than an inch difference in diameter.

I run 255/40R18(about 22.2") and 285/40R18(about 23.2") and have no problems.

 

whats the widest 18 inch rim/tire combo that would fit on a 2003 gt?

 

Tire diameter differential is indeed a problem, when it gets to a certain point. I forget the percentage, but is around 1". I woud be willing to bet that if schmalls really gets on the brakes, the ABS will act up sooner than otherwise due to rotational differential in speeds between front/rear.

If the tires are the same diameter, it will make zero difference to the ABS in any way. If you like this look.... GFI

As for what will fit well....? A very common combo is 9"s & 10"s

Jazzer

 

Once again Jazzer speaks knowledge....

 

I don't have these slotted rotors for nothing, I'm on the brakes pretty hard now and then.

 

I don't have traction control, I might not have ABS either.

 

I know you can fit an 11" rim in the back with no trouble. 315s are probably your best bet as I have never seen 325s and 335s would be a little big.

 

Sounds like you may not have ABS. As I understand it, not all New Edge rides came with them or TC. I think if it has one, it will have both and since no TC, probably no ABS either.

Have you peeped my Brakes upgrade thead, mister?

 

my 2000 gt has abs but no tc