MonsterZ28

Im gonna get TTIIs 17x8.5 front and 17x11 in the back

what is a good tire size

And would someone please explain what the numbers mean
I know the last numbers are rim size.... i think

Fulton 1

iTrader: (9)

Well for the 17x11's the right size is a no-brainer - 315/35/17. The 17x8.5's are a little bit of an oddball size, though. Most folks use 17x9 or 17x9.5 wheels up front, which works well with a 275/40/17 tire. However, every tire manufacturer that I've checked lists the minimum wheel width for the 275's at 9", so you'd probably be better off going with a 245/45/17 or 255/45/17 on the 17x8.5" wheels. The 245/45/17 is going to be the closest to the same overall diameter as the 275/40/17.

As far as the numbers go - lets use a 275/40/17 tire as an example:

1) The "275" part is the nominal section width of the tire (sidewall to sidewall) in mm. So a 275 tire would have a nominal width of 275mm (10.83"). Of course since this is a nominal dimension, it'll vary from manufacturer to manufacturer.

2) The "40" part is the ratio of the sidewall height to the tread width. So a 40-series tire will have a sidewall that is 40% as tall as the tread is wide.

3) The "17" part is the diameter of the wheel that the tire is designed for.

Of course there are other things to consider as well, such as speed rating, tread life, etc. FWIW, Tirerack has some really good tech articles, so it may be worth your time to do some research on their site - www.tirerack.com