OK, I will attempt to lay this out quickly & in a way that most will understand.

Lets start with backspacing on a wheel, this is very simple to measure. Take a straight edge of some sort and lay it across the back of the wheel, make sure if a tire is mounted on the wheel it does not interfear. Then take a ruler or tape measure & measure from the back of the mounting pad (area that has the holes for the wheel studs) to the straight edge. This will give you the backspacing of any type wheel you are measuring. Backspacing was mainly used as a way of telling how the wheel will sit on the vehicle, how far it will stick out or inside a fender by the amount of backspacing. So, if the backspacing is a smaller number like 3.5" then a wheel will normally have a very wide stance by sticking out on a normal vehicle(creating a deep dish wheel). You will not normally see any backspaing less than 3" due to the fact of the wheel will have no strength left. Most older cars & trucks used the backspacing method. The higher the backspacing, say 6" the more the wheel will tuck inside the car or truck(creating a flatter face wheel with less depth).

Now, Offset is much the same. Offset is measured in millimeters insteaad of inches like backspacing. Instead of measuring from the mounting pad to the the back edge of the wheel to get the backspacing. This is a little more difficult to do by hand, lets say you have wheel standing up on the floor (No tire on it) if you measure the width of the wheel across, say it's 8". Make a mark on the wheel at 4", OK this is your center of the wheel barrel. Correct? So if that mark went directly through the wheel to be dead even with the back of the mounting pad you would have a 0 offset. If the mounting pad was more towards the back of the wheel, behind the center mark you made then you have a negative offset( smaller backspacing) If the mounting pad is closer to the front or face of the wheel then you have a positive offset (flatter faced wheel) See how the above backspacing & offset are similar?

Most of todays front wheel drive cars & some rear wheel drive are a positive offset (Flat face wheel with no depth). Yesterdays cars were all negative offset & had that nice deep wheel that everyone loved.

Todays trucks are also getting on board with the positive offset thing, that is why you see most of the trucks 05 & newer coming with flat looking faced wheels. They are a high positive offset, they have designed these newer trucks with a wider suspesion for better stability & it creates less stress on parts. The positive offset wheels are made to basically wrap around your braking system. If you are lifting a newer model truck talk to your wheel sales team for what will work best for your lift size & truck. Hope this helps!

Mike Mashburn

President RIMZ ONE

1-800-710-9411