I finally upgraded to my old Bridgestone Potenzas RTF's to no RTF Michelin pilot sport 4s in 255/40 and 295/35 on the stock 21" 718M wheels. Mounting was done without any issues and the ride is much smoother and quieter. I really like slightly meatier sidewall especially on the rears. During higher speeds, car feels more planted but I do feel the turning is slightly slower with this staggered set up. Regardless, I wish I have switched long time ago but was worried with fitment issues. I have 0 rubbing at full turn and I am lowered on H&R springs.
With this set up I’m still at .3% difference between front and rears.

Nice! Congrats mate, definitely the tyre choice I'll be going with also.

_ink wrote

Nice! Congrats mate, definitely the tyre choice I'll be going with also.

Can you take a few more of the tyre side on so we can see the overhang better ?

According to equivalency tables, maximum with for our rear rims (9.5") is 275 mm...

Don't you think it can be a bit dangerous when cornering fast?

davidoff86 wrote

Can you take a few more of the tyre side on so we can see the overhang better ?

I’ll take some better pics today

comber wrote

According to equivalency tables, maximum with for our rear rims (9.5") is 275 mm...

Don't you think it can be a bit dangerous when cornering fast?

Different brand tires with better than other. Tire installer told me there was 0 problems or concerns when he was mounting them. I have done ton of research before purchasing this set, so I was very confident.

For example, X3M people are running 295's on the rear as well, and their wheel is 10" wide so not whole lot difference.
The only concern I would have is doing 265's on the front as it would rub against the strut. I put my hand there, and without any spacers there is only little room left. With that said, no rubbing at all at full turn, but I do plan on getting some spacers for more flush look in the future.

what made you go with 295 on the rear ?

They do a
275/35 ZR21 (103Y) XL
and a
285/30 ZR21 (100Y) XL

davidoff86 wrote

what made you go with 295 on the rear ?

They do a
275/35 ZR21 (103Y) XL
and a
285/30 ZR21 (100Y) XL

Those won't work. I did my research.

davidoff86 wrote

what made you go with 295 on the rear ?

They do a
275/35 ZR21 (103Y) XL
and a
285/30 ZR21 (100Y) XL

Diameter difference between front and rear must not be higher than 1% in our xDrive system...so with 255/40 at front none of them will work.

You can check it in websites like this: https://tiresize.com/comparison/

Looks great! I see that you have spacers installed. What width are they and did you need to realign the steering geometry?

atrueb wrote

Looks great! I see that you have spacers installed. What width are they and did you need to realign the steering geometry?

thanks. I don't have spacers installed but plan on doing 12mm all the way around

So 255 45 20 and 295 40 20 should be similar to your % X drive difference with the 21"?

suby01 wrote

So 255 45 20 and 295 40 20 should be similar to your % X drive difference with the 21"?

255/45 wouldn't work, it would be at 3% circumference different. see comparison photo below

So 1% is the max for our cars?

not bad. Wish I could cram more rubber in the front, but think I am near maxed out. even going to a 20mm would be hard to get to 285 let alone 295. But with no spacers running 295 in the rear, that tells us we can run 305s in the rear (yes with different wheels) and give us the same staggered setup as the x5 if we so choose. just thoughts. But nice info

Torinalth wrote

not bad. Wish I could cram more rubber in the front, but think I am near maxed out. even going to a 20mm would be hard to get to 285 let alone 295. But with no spacers running 295 in the rear, that tells us we can run 305s in the rear (yes with different wheels) and give us the same staggered setup as the x5 if we so choose. just thoughts. But nice info

You have 275 in the front?

suby01 wrote

So 1% is the max for our cars?

It’s what’s considered safe and approve by bmw

suby01 wrote

You have 275 in the front?

yep.

Torinalth wrote

suby01 wrote

You have 275 in the front?

yep.

You could have had the 275/285 if you went for something less than 255 at the front though. I checked myself and was getting only a 7mm difference in diameter

That does look much better and probably what I'm looking to do as well. Can you take a picture of the tire flushness and one further back from the side to see the whole car?

nice ! thank you for sharing!