another 20" wheel question

wazz up? i did a search on this topic but did not get a sure answer becuase there was alot of doubt on the issue. i want to lay frame with stock mazda hubs but i want to run 20x8's what is the right backspacing i need both in inches/milimeters? some said +38.. some +40 what about 6.5"? please help me out

you need +46 offset or 6.5" of backspacing.

if its only 6 off on the offset you can more than likely roll your fender a little bit and get away with it.

the whole backspace/offset question is really application specific. depends on your wheel width and even tire size/bulge.
what you need to be worried about is frontspace. thats the distance between the WMS to the outside of the wheel. measure from WMS to the inside of the fender, and subtract half an inch. that'll be your frontspace. now subtract the frontspace from the overall width, and that's your backspace.

backspace/offset i know it depends mainly on wheel width and tire size but i was specifically asking on the 20x8 rim with stock mazda hubs. i'm planning in running 205/30's or 35's tires. thank u 4 all the input!

who makes a 205 series 20" tire?
205 is too narrow for an 8" wheel anyway. a 205 is more for like a 6-7 inch wide rim.

guess i missed that. my bad.

what?, you don belive me, for what I know and my little experience with mazdas, 7 inch wide needs about +32, 7.5 about +39, 8 about +46 and 8.5 would need as I said, +54. Which you cant get in 6 lug without buying a 3000 dollar set of billets. Redrill to 5 lug, lots of high offset 20's on 5 lug