Can anyone tell me if 265x50 tires with 18x9 wheels will work on an 05 GT? Thanks for your help!

 

sure it will work, a little larger in diameter than stock. Check fron turning clearance tho, but should be ok.

 

255/45/18 on 18x9 fit like a glove on mine. Same outside diameter as the stock 235/55/17, so I didn't have to reflash the computer to correct the speedometer. Your size is close, but it is different, so you may have a slight difference in outside diameter, which means you may have to reflash (if you don't have a tuner, you'll need one), or your speedometer may be wrong.

I wanted to add that my rims have a 25mm offset. I'm not sure what you have, but the issue with turning radius is related to the offset more than the size.

 

Well since this looks like a good time to ask, What is the minimum/maximum/optimum offset that we should be using to make sure our tires dont rub? I will eventually be going up to 19 inch rims, and am looking at 265/40/19 for tire size. It is the closest I can get to stock size, so how much offset should I get?

 

It's a 6" backspace 24mm offset