I have an '04 Screw FX4. Am I right that my wheels are 18x7.5 with 5.5 backspacing? (I know they are the 18"s) And if I go to a 20" wheel with a little less backspacing, say 5", I will open up a little clearance on the inside of the rim for larger tires, and the tire will protrude a little more out of the wheel well? How does the wheel width play into the amount of backspacing? Are there any good places to read about this stuff to learn the basics? Thanks, hope you guys can help!

 

Welcome to the site! Yes, you are correct on the stock backspacing. If you go to 5" BS, the tires/rims will stick out farther than stock. I have 18x9 with 5" BS, and they stick out about 2" farther than stock. Heres a link that I got from the forums that may help...
http://www.bigcustomwheels.com/rt_specs.jsp

 

Thanks for the link - very helpful!

 

np