Just wondering what size tires i should use on my 05 mx6 with an 18in wheel and a 42mm offset? Didn't know if i would have to roll the fenders or not and would a 225/40 work at all? Thanks

 

I highly doubt it.The 6 series has even less fenderwellroom to play aroundw/than the 3 series does
The OE spec for offset is +60mm, and the OE wheels are 17"x7's. Though you don't mention the width of these wheels, I'm guessing you would probably have to trim the fenders (cut them back) in order to gain clearence for those.
And if nothing else you'd probably feel a difference in steering, handling, tracking and bump steer... and not for thebetter either.What you may not feel is that it could take longer to stop as well.
Getting that far away from OE on the offset is not a good idea. I wouldn't even put +42's on my 3 series, OE offst = +52.5mm.

 

so if i roll the fenders would that keep them from rubbing the width is 7.5 and what tires should i use?

 

I ran RX-8 18x8 wheels and 225/45R18 tires with no rub problems on my wife's 6 Sportwagon. (They're for sale)

 

You're not hearing me.... STAY AWAY from wheels that only have a +42mm offset on your 6.

The RX8's have a +52.5 too don't they SST? What is the offset?
And I love the shameless promotion there too.

 

Not sure on the offset....the recommendation I got from my friend who works for Mazdaspeed was don't go wider than 7.5" with 52.5mm offset, my wife's front tires would rub a little on a "friendly surface" when turned to full lock, but we rarely ever do that so it isn't a problem.

A guy's gotta try

I'd recommend around a 48-60mm offset depending on the wheel width.