New wheel...
 

Hey guys, I have a 2004 X5 4.4i for a little over a year now and very happy with the X. When I bought it last year, I also bought 4 new shoes 255-55-18 but once the summer is over so the tire are, I did 2 summer with those.

In the next few months I'm going to buy a new set of wheel for spring 2011. I'm thinking of 20's staggered, 20 x 8.5 front and 20 x 9.5 rear, now what would be the ideal tire size ? I've did much research but came with different option, in order to keep the speedometer as accurate as possible, what do you think of these size which will throw the speedo off by less than 1%, so my idea is to get 275/50/20 front and 305/45/20 rear does that make sense ?

Thanks for any good advise beside telling me to search. Lol

AA

Using the handy dandy BMW Wheel Pic site, pasted below, I see that
the oe style 20" wheels for X53, use 9.5 x 20 for fronts, and 10.5 x 20
for rears, not the narrower 8.5/9.5 you are interested in...

Even the 19" oe style 132s, staggered, use 9" fr and 10" rear...

If you simply have your wheel widths off/typo, then the standard tire
fitment for 20 inch staggered oe style wheels is:
275/40R 20 frt
315/35R 20 rear

That combo is nuts on to any oe BMW wheel/tire combo, too.

If you really are after that "odd"/less width wheel size in 20s, then
it would take some calculating using the ol' tire size comparo, also
pasted below.
My 50Cts...
GL, mD

Wheel Pics site, (just use the top drop down box for E53):
Felgen-Katalog - BMW-Treff - der Treffpunkt fr alle BMW-Fans und -Fahrer

And, the handy tire size change comparo site,
(there are several on net, but this one is simple
and elegant, imo):
Tire size calculator

Hey motordavid, thanks for your input. Yesterday I did some more search and found out what you just stated, my bad for thinking it was 8.5" in front, anyway 275 looked a bit wide for 8.5" rim. Sorry I dont have that much knowledge with BMW since this is my first bimmer. I will then look for the size above mentioned.

Thanks again & have a good one.

AA