08 GT with factory 17" rims. Need to upgrade the rubber size. Besides lowering the car, I want to fill up the wheel well as much as possible. What the most extreme tire profile for the 17's?

 

I have always felt that upping the profile to fill a wheel gap, is a bad idea for a couple reasons

You lower the car, only to raise it back up with lower profile tires and effectively up your final drive gear ratio. You will also need to address speedo/ODO accuracy, but that is not a big deal at all.

You won't be able to achieve a Lexus, Porsche or the like look, as the fender wells are not designed the same way. Do you have an example of how you want it to look?

What kind of driving do you do?

Jazzer

 

Mostly highway. I have old school Mopars where I can tuck the tire just inside the wheel well and just hide the top of the tire with the fender/quarter panel. Actually what you have in your pic of the white stang.

 

That is my car and under a serious lateral load at the time. In fact, the under carriage is actually draging a bit on the ground as well (I heard it!). If it were to be like this at all times, it would be litterally impossible to drive on the street As it is, I have less that 2.25" of clearance underneath in many locations.

I don't see you being able to hide the top of the tire, unless you maybe removed the liner under there. The fenders are just not designed like the European rides one sees with that "hella flush" look.

Look up your OEM tires and see the diameter. You can maybe push that 2" larger diameter, but would not go more and especially if lowered.

Jazzer