This is something i have always pondered,if my a4 has an offset of 43 and the a3 wheels are 54 then yes there is a difference of 11,but given that the a3 wheels are 7.5 as opposed to 8 inches then there is roughly 13mm difference in wheel width alone,so where does this 13mm go?
Is it split 6.5mm either side or does the full 13mm add to the 11mm making the wheel sit 24mm into the arch?
Slightly confusing as you need to know what thickness wheel spacers to buy and what length wheel nuts as well.hmmm...