are all brake pads from 1986-1991 interchangeable? i'm on a budget right now and there are some decent ones at the car yard that i can pick up for like $2 each. the cars at the yard are s4, but i have an s5.

 

They're all the same. Just remember that there were both single and 4 piston calipers used, so by pads to match.

 

Nope they differrent

 

No.

4-pot front calipers between years? Identical

Single piston front calipers between years? Identical

Single piston rear calipers between years? Identical

All you have to do is buy the right pads for the right type of caliper. The only thing year affects is what models had 4-pot vs. single piston front brakes.