I have a 1983 Oldsmobile Cutlass. I am looking to 20" staggered Rev Classic 100 Anthracite wheels on the car. I need to know the backspacing and tire size that would work. Also would I need spacers? I have searched the site for the answer and either I did not see it or do not understand. Thanks in advance .
The ideal offset is about +5mm in front and about -7mm in back. These numbers are close to zero, so Zero offset wheels wheels generally work with a "square" set up, as long as the wheel width isn't much more than 8".
If you upgrade to "big brakes" in front, these generally push the the front end out about 9-11 mm, so this would make the ideal offset in front about 15mm, which pushes the difference in ideal offset from the front to back to almost 1" (21-23 mm difference vs. 25.4mm = 1 inch), which is about the minimum wheel adapter width..
With a staggered set, you don't have to worry about a compromise offset, so look for wheels with zero to -10 in back and Zero to +10 in front.
As you go up in width of wheel (above 8") and tire (above 225 in front, 255 in back), the ideal offset range narrows.