I have a set of 215-45-17 hankook ventus tires and wanted to get a set of silver 5zigen Fn01r-c 17x7(you can find a picture of them at edgeracing.com) My question is what offset would be better 35 or 42?

I currently have a set of 16" Enkei WDM's with a 42 offset with the stock tires and that it can be brought out a little bit more towards the fenders.....So should I get the 35 or would it stick out to much?

 

that's less than 10mm change which is approx 1/4 inch out further towards the fender not much change but in the right direction 7mm = 0.275 inches,,, 10mm = 0.393 inches
http://education.yahoo.com/reference..._and_measures/

 

Smaller offset sticks out more.

 

Well, since the rim size is the same, and the only difference is the offset, then the difference is 7mm further out if you go with the 35mm offset. If you go with the 42mm offset, it will be the same as the Enkei's you already have...

You can go to this link and see what the difference is between your current one and the new one. This is good if you're going with different rim width's.

http://www.1010tires.com/WheelOffsetCalculator.asp

BTW, I run a 7.5" rim with a 42mm offset, and it's perfectly fine... I don't see a problem with going out 1mm more ;)