[wennbom]

Hello Norris,
I’m also considering a set of 21”

It is a set of Vossen HF2
9x21 ET32 with 255/35 R21
10.5 ET42 with 295/30 R21

My first thought was that “those will never ever fit the car”, but seeing yours give me some hope.

Was your car lowered in the pictures above?
My car has the passive m-sport suspension.

Cheers
Michael

[jps0429]

Originally Posted by ozwol

Discussed this (as id prefer the look of a taller tyre on the 20's) with a former bmw master tech who advised against it ...he said the cars are mapped to a certain circumference tyre and this could cause overgearing and drivetrain wear.

I spoke to someone at my local dealer who told me the same thing. Not sure what to do. I want a 21inch wheel but that means I would have to go with a 30 front and 25 rear height tire

[jps0429]

Originally Posted by Norris83

I have the 7 series wheels.
Fronts are 8.5" x21" offset is 25mm
Rears are 10"x21" offset is 41mm.

The front tires have slightly rubbed a few times when I'm backing out of a steep driveway while I turn a certain way. If I'm going straight no rubbing at all. Only when I'm in reverse with a passenger in the front and half a turn to the left. Towards the end of the summer they weren't rubbing anymore. not sure if it was because the tires wore out or the inner fender liners wore out lol

These were on a 2017 540i xdrive, m sport suspension, didn't have the adaptive suspension.

I will be trying this setup in a couple of months on my 2018 M550i which has the adaptive suspension. It sits slightly lower. So hopefully it doesn't rub any where else.

Are you running 21inch wheels on your M550i? I am thinking of getting a set of 21s for my M550i but just nervous about the tire setup. A service tech at my local BMW dealer told me a 35front/30rear height tire on 21s would throw an xDrive error message?

And 30front/25rear make me nervous with potholes

[wennbom]

I have responded in the other thread you started, but yes it works without any issues even if you lower the car a bit more.

[wennbom]

I can confirm
Vossen HF2 with Conti Sport Contact 6
9x21 ET32 with 255/35 R21
10.5 ET42 with 295/30 R21
on both G30 and G31 lowered with H&R kit works without any issues

[Norris83]

Originally Posted by jps0429

Are you running 21inch wheels on your M550i? I am thinking of getting a set of 21s for my M550i but just nervous about the tire setup. A service tech at my local BMW dealer told me a 35front/30rear height tire on 21s would throw an xDrive error message?

And 30front/25rear make me nervous with potholes

Sorry for the late response. Never had any error messages for the xdrvie. The key is to keep the same overall tire diameter front and rear axles.
I've noticed that on the M550I when I reverse and turn the wheels a certain way it rubs slightly in the fender liners. When you're reversing the car tends to go lower from the front and higher on the rear and that's the only time it rubbed.

[Norris83]

Originally Posted by wennbom

Hello Norris,
I'm also considering a set of 21"

It is a set of Vossen HF2
9x21 ET32 with 255/35 R21
10.5 ET42 with 295/30 R21

My first thought was that "those will never ever fit the car", but seeing yours give me some hope.

Was your car lowered in the pictures above?
My car has the passive m-sport suspension.

Cheers
Michael

My car was on stock M passive suspension.

[jlcf22]

Originally Posted by wennbom

I can confirm
Vossen HF2 with Conti Sport Contact 6
9x21 ET32 with 255/35 R21
10.5 ET42 with 295/30 R21
on both G30 and G31 lowered with H&R kit works without any issues

Have any pictures?

[Knifeedge2k1]

Originally Posted by ozwol

Discussed this (as id prefer the look of a taller tyre on the 20's) with a former bmw master tech who advised against it ...he said the cars are mapped to a certain circumference tyre and this could cause overgearing and drivetrain wear.

This guy is a master bullshitter then

This mod amounts to a 3.5% overdrive. Spacing between gears is something like 15to25%.

So running a 3.5% overdrive amounts to less than 1/5th of a gear on average. Just leave it in sport mode and you've literally solved the issue.

[Boosted_8]

I'm thinking of changing the Eagle F1 245/35/20 & 275/30/20 runflats on 668M wheels (M550i) to 245/40/20 & 275/35/20 Pilot supersports. It doesn't seem like this will cause drive train errors as the ratio between axles is the same as before?

[Norris83]

Originally Posted by Boosted_8

I'm thinking of changing the Eagle F1 245/35/20 & 275/30/20 runflats on 668M wheels (M550i) to 245/40/20 & 275/35/20 Pilot supersports. It doesn't seem like this will cause drive train errors as the ratio between axles is the same as before?

You won't have any issues.

[BD550]

Originally Posted by Boosted_8

I'm thinking of changing the Eagle F1 245/35/20 & 275/30/20 runflats on 668M wheels (M550i) to 245/40/20 & 275/35/20 Pilot supersports. It doesn't seem like this will cause drive train errors as the ratio between axles is the same as before?

I recently put non run-flat Conti's 245/40/20 front and 275/35/20 rears on my M550i with 668M wheels with no issues whatsoever. And they ride great.

[Boosted_8]

Last question for those that have already upsized the tyres. Was the acceleration noticeably affected? Looks like + 4% longer gearing with the taller side wall.

[cna90]

Finally got myself a set of 648M with 7 Series tire sizes. These wheels have been on my list since I got the car but never been able to get my hands on them for a good price.
It’s amazing how much the ride height increased over stock while filling the fenders.
I think now I definitely gotta get the front lip.
Can wait for summer to put these on.

They are close to flush to the fenders, specially the fronts. I would have loved it more if the back was further out but I think 295s will solve that. For now, the 275s will do.

5er should have come with these from the get-go in my opinion.