rear tire size help

[gnlover2]

looking for what size radial tires will work on the rear. 235/60-15 on the frontand want to use either 245or 255-60/15s on a 7.5 centerline rim?my gn has a ultra chip and your basic bolt ons. thanks for the help , oh will the gear ratio change much to make a diff?

 

[azbob]

255/60/15 will fit and your rear end ratio will change from 3:42 to 1 to 3:31 to 1

 

[gnlover2]

will that help me or hurt ,as far as the ratio

 

[azbob]

Your speedometer will read about 4 mph low but otherwise the change should not be noticable.

 

[gnlover2]

ok cool,so it should not make the lower rpms or off the line takeoff slower

 

[turbojd]

255-60-15 is what I have on my GN right now, on a 15x7" rim, it does make the speedo read about 3 or 4 mph lower than what your really going as was said above, not a big deal to me.

 

[gnlover2]

so off the line , the car should still be ok??the 1 extra inch in dia. should not matter much?

 

[UNGN]

so off the line , the car should still be ok??the 1 extra inch in dia. should not matter much?

With street tires, once the turbo spools, the taller the back tire is the faster the car will be.

A taller tire will spin less than a shorter tire. With street tires, spinning tires is what slows a T/R down, not rear gear ratio.

with a 28" tall tire vs. a 26" tall tire, the car may feel a little more sluggish until the turbo spools, then you'll notice it spins the tires less and you have to back off less to get the tires back if they blow off.