[Budget M3]

I have a leased 340i and want to ditch the run flats (put the expensive to replace RF's on the shelf until lease turn-in time). I have a set of Momo Arrow 17x8 ET35 wheels in the garage from an old E36 that I want to fit to the F30. The width and offset are almost exactly the same as the stock 18x8 ET34. According to my tire calculator, 255/45R17 is almost exactly the same circumference as the stock 225/45R18, but they are ~1.2 inches wider than the stock tires. So my questions are:

1. Will 17x8 ET35 Momo's fit over the stock (non-M) front calipers on the 340i?
2. Will the wider 255 rubber on the 17's stick out too far on the front fenders? If anyone has pics running 255 width on the front of your car (regardless of wheel diameter), I would love to see it.
3. Can the TPMS sensors be swapped from the stock wheels to the Momo's or am I best advised to buy new sensors for the 17's?

All advice and opinions appreciated (except those that say I am crazy for wanting to downsize my wheels! &#128521

[goj]

Rears won't fit. And 255 is too wide for 8 inch wheels.

Just get non runflat tires. They will be much softer.

[Budget M3]

Originally Posted by goj

Rears won't fit. And 255 is too wide for 8 inch wheels.

Thanks for the reply. Hopefully you can provide some additional info to clarify your statement.

I am more concerned with the front and would think the rear would be the least problematic fitment. According to 1010tires calculator, the minimum wheel width for 255/45r17 is 8-inches, so the tires should fit the wheel. Why do you think 255 is too wide for 8-inch?

Why do you say the "rears won't fit"? The same exact wheel width is within 1mm of stock offset for the same width which tells me there should be no problem with clearance of the wheel itself. BMW OEM fits a 255 width tire on the rear with a 8.5 inch wide wheel so it seems pretty close.

[Amused]

Do you have the track handling package?

[Budget M3]

Originally Posted by Amused

Do you have the track handling package?

I do not. The base 340i front rotors and calipers look pretty large though.

[goj]

255s are too wide. The will not fit. The minimum wheel width is 8.5. Check out tire rack. The front will fit fine assuming you don't have track pack.

The rears won't clear the brakes without spacers.

I'm telling you, put on some Continental tires as the ride is a bit softer but still have pretty good handling characteristics and keep the 18s.

[Budget M3]

Originally Posted by goj

255s are too wide. The will not fit. The minimum wheel width is 8.5. Check out tire rack. The front will fit fine assuming you don't have track pack.

The rears won't clear the brakes without spacers.

I'm telling you, put on some Continental tires as the ride is a bit softer but still have pretty good handling characteristics and keep the 18s.

I find the tirerack site to be very helpful for most things, but cannot find a simple calculator like the 1010 site or discounttiredirect (both of which have calculators that say 255 will fit on 8-inch). Now you have worried me with conflicting information from a reputable source, tirerack. If 255 is indeed too wide, then what does tirerack say is the widest tire that will fit on a 17x8 and maintain ~26-inch circumference ( plus no more than 2%)

Really, a 1mm difference in offset will not clear the rear brakes? Seems hard to believe. I can envision how the width of a 255 might create clearance issues with the suspension, but not the brakes.

You are preaching to the choir with respect to RF vs conventional. I know I want to replace them and keep the $300/each RF on the shelf until lease turn-in. Running non-RF without a spare, however, is not my style. I planned to use one of the 18's with RF as the spare. Obviously that plan does not work if I have to reuse all 4 existing rims with new tires. No way you could have known that from my original post, though.

Oh, and the stock 18 rims are nice enough, but not really all that special IMHO. It would be nice to see something different on there and I've always loved my Momo Arrows.

[.BMW.]

255/45 is approved to be used with 8" wide wheels.

255/40 (or lower profile) need minimum 8.5" wide wheels though!

[goj]

Originally Posted by .BMW.

255/45 is approved to be used with 8" wide wheels.

255/40 (or lower profile) need minimum 8.5" wide wheels though!

Fair enough. I stand corrected I suppose I was looking at specs for your OE wheels

[Budget M3]

Originally Posted by .BMW.

255/45 is approved to be used with 8" wide wheels.

255/40 (or lower profile) need minimum 8.5" wide wheels though!

Thanks for the clarification. This confirms the data from the tire calculator I'm using.

goj, if you agree with this do you still believe there will be clearance issues front or rear?

Still looking for an answer to the original question about TPMS....

[goj]

Originally Posted by Budget M3

Thanks for the clarification. This confirms the data from the tire calculator I'm using.

goj, if you agree with this do you still believe there will be clearance issues front or rear?

Still looking for an answer to the original question about TPMS....

I think you may need a spacer on the rear. But should work.

As for the monitors I don't know

[Budget M3]

Originally Posted by goj

I think you may need a spacer on the rear. But should work.

As for the monitors I don't know

Thanks. I'll keep looking for info to confirm rear suspension clearance and sensor info.

[wdeerfield]

If you already have these wheels with tires on them, why dont you just bolt them up and see for yourself? seems odd to have the wheels and tires and still be asking all these questions. 10 minutes in the garage with a jack will answer all your questions. You'll want to make sure the offset clears the brake caliper on the inside of the spokes as well.

[Budget M3]

Originally Posted by wdeerfield

If you already have these wheels with tires on them, why dont you just bolt them up and see for yourself? seems odd to have the wheels and tires and still be asking all these questions. 10 minutes in the garage with a jack will answer all your questions. You'll want to make sure the offset clears the brake caliper on the inside of the spokes as well.

Ahhh, if it were only that simple. I have the wheels but no tires at this time, hence the questions.

BTW, the tone of your message basically implies I am an idiot for "asking all theses questions". It is NOT appreciated nor is it in the spirit of this forum where no question should be considered stupid. We are all just enthusiasts of differing levels of experience and expertise. Even though it would not work for me, you could have easily made your point about test fitting them with only the first and last sentence. Rant over...