Wheel Tire Upgrade

[Sonic04]

Hi All,
Running basically a stock 2004 GT, save for some easy engine bolt-on's.
This is my daily driver and I like to get out a couple of times a year to a road course.
I'm looking at a wheel/tire upgrade and do not want to give up much in ride comfort, thereby shaking my fillings loose over potholes and expansion joints.
Does anyone have some feedback on comparing the stock 04 cobra wheel/tire to, say a 275/35/18?
I'm a little concerned over the 35 series profile. So far as I can tell, the contact patch is near the same in this comparison.
Anything additional on running a staggered 285 or 295/35 in the rear?
I do plan on updating the rear to a 3.73 gear, and would like to do some suspension upgrades in the future.
Thanks

 

[Mustang5L5]

The two sized you are comparing, 275/40/17 vs 275/35/18 will have the same contact patch width, and overall diameter. The 35 will have a shorter sidewall to make up for the increase in rim diamter. Anytime you go with a larger rim, and reduce rubber sidewall, you end up with tighter handling, but lose a bit of ride comfort and traction due to sidewall flex.

 

[wms004]

I'm running 275/35/18 on 18x9 w/ 3.73's in the rear. Go with Maximum Motorsports Lower Control arms if you're looking to improve rear suspension.

You'll need at least an 18x10 wheel in rear to run 285/35 or 295/35. See tirerack.com and click on specs for a tire and you'll see the allowed rim ranges.