Thread: Can someone explain offsets for me?

I was looking at a bunch of 18" wheels, but I realized that I know next to NOTHING about offsets. +35mm, -20mm, etc. None of it makes any sense to me. But from what I gather, certain offsets require the fenders to be rolled, and some don't.

Can someone explain to me about wheel offsets? I am totally lost.

The wheels I was looking at getting are either 18x8, or 18x8.5, with 5x115 bolt patterns, and +35mm offset. Will the fenders need to be rolled for these?

Here are some of the wheels I was looking at....

18" wheels Pontiac Grand Am Grand Prix Montana Saturn : eBay Motors (item 150425414636 end time Mar-30-10 02:49:48 PDT)

GA 18 HS ST-11 WHEELS RIM 5 LUG GRAND AM PRIX ALERO CTS : eBay Motors (item 130372161269 end time Apr-04-10 10:12:36 PDT)

GA 18 CH ST-11 WHEELS RIM 5 LUG GRAND AM PRIX ALERO CTS : eBay Motors (item 130372292493 end time Apr-04-10 21:15:11 PDT)

off set is how far the center hub mounting pad is spaced in relation to the direct halfway point of the width of the rim....

in other words if your rim has a +30mm offset then the center is +30mm towards the outside edge of the rim..... 0mm offset is dead center and anything toward the inside of the wheel is negative.

heres a good reference for you to understand visually.

https://www.rsracing.com/tech-wheel.html

1st set- you MIGHT be able to run those without fender rolling if you do a 245 tire.

2nd & 3rd- def gonna have to roll fenders most likely esp. if you lower...a 245 tire might let you run them unrolled if your not lowered.