[PagedAtol17]

Hey guys I just got a set of 351m wheels and they are a square setup with the 19x8.5 setup so what tires are the best? Right now I'm thinking Goodyear eagle LS2 Run Flats all season. WHAT SIZES CAN I PUT ON THESE RIMS BESIDES 245/40/19 & 255/40/19??? Or are those the only 2 sizes I can run?

I am looking for run flats as well as all season and I know the backlash but I have a lot of pot holes and am moving back to Michigan and then Knoxville TN in the fall so say what you want but I am getting Run flats and all seasons. Appreciate any help and input

[cdmulders]

Two points:
1. You can go 245/45/19 on all four with your 351m wheels, no problem at all. I did the equivalent setup with my winter tires and they thickened the sidewalls with associated improvement in ride.
2. Unless the Goodyear LS2 Runflats have improved (which is quite possible) I would not recommend them based on my experience. These came with my new F10 back in 2012, and they are quite fragile to blistering upon moderate impact with potholes. They also don't have the best handling and the ride is somewhat harsh (my subjective opinion, of course). Many have provided good feedback in this forum for the Michelin all season runflat tires.

[PagedAtol17]

Originally Posted by cdmulders

Two points:
1. You can go 245/45/19 on all four with your 351m wheels, no problem at all. I did the equivalent setup with my winter tires and they thickened the sidewalls with associated improvement in ride.
2. Unless the Goodyear LS2 Runflats have improved (which is quite possible) I would not recommend them based on my experience. These came with my new F10 back in 2012, and they are quite fragile to blistering upon moderate impact with potholes. They also don't have the best handling and the ride is somewhat harsh (my subjective opinion, of course). Many have provided good feedback in this forum for the Michelin all season runflat tires.

But I thought the max you can do for tires is the 245/40/19? I read on other posts that if u do 245/45/19 since the diameter is over 1% different it'll change the speedo and affect it?

[cdmulders]

Originally Posted by PagedAtol17

But I thought the max you can do for tires is the 245/40/19? I read on other posts that if u do 245/45/19 since the diameter is over 1% different it'll change the speedo and affect it?

I'm not sure but you may be conflating some things. It is true that for an xDrive, the front tire diameter should be less than 1% different from the back tires. This is to prevent damage to the transfer case. There is no such limit on changing the diameter (and of course, circumference) of all your tires at the same time, as long as they match front to back, and as long as the tires are not going to rub on something. On this point, as I already said, I had no difficulty in up-sizing the tires to a larger diameter, and I know of others on this forum that have also done that without any problems.

Second point - yes, the larger diameter tire will indeed cause your speedometer to read lower than it was for the same actual speed. Given that most modern BMWs appear to already read higher than actual (average seems to be around 5%) you could very well make your speedometer more accurate by upsizing your tires. This was exactly my experience when I upsized my tires.

So you are not guessing, I recommend you try different tire sizes on a wheel/tire calculator, like this one to get a feel with what goes on when you change tires sizes.

If, however, you are just looking for advice on what tread width of tire you can go (besides just 245mm) then there are certainly others with more experience on that topic than me. I did successfully change my rear tires to 275/35/19 to match my front tires of 245/40/19, thereby creating a staggered setup with the rear wheels being wider than the front by 1".

[PagedAtol17]

Originally Posted by cdmulders

I'm not sure but you may be conflating some things. It is true that for an xDrive, the front tire diameter should be less than 1% different from the back tires. This is to prevent damage to the transfer case. There is no such limit on changing the diameter (and of course, circumference) of all your tires at the same time, as long as they match front to back, and as long as the tires are not going to rub on something. On this point, as I already said, I had no difficulty in up-sizing the tires to a larger diameter, and I know of others on this forum that have also done that without any problems.

Second point - yes, the larger diameter tire will indeed cause your speedometer to read lower than it was for the same actual speed. Given that most modern BMWs appear to already read higher than actual (average seems to be around 5%) you could very well make your speedometer more accurate by upsizing your tires. This was exactly my experience when I upsized my tires.

So you are not guessing, I recommend you try different tire sizes on a wheel/tire calculator, like this one to get a feel with what goes on when you change tires sizes.

If, however, you are just looking for advice on what tread width of tire you can go (besides just 245mm) then there are certainly others with more experience on that topic than me. I did successfully change my rear tires to 275/35/19 to match my front tires of 245/40/19, thereby creating a staggered setup with the rear wheels being wider than the front by 1".

So for my 2015 528i xDrive if I do 245/45/19 Michelins on the square 351m 19x8.5 it should be fine?

[cdmulders]

Originally Posted by PagedAtol17

So for my 2015 528i xDrive if I do 245/45/19 Michelins on the square 351m 19x8.5 it should be fine?

In my humble opinion, a definite yes. You should be fine.

[Blue Angel]

Originally Posted by cdmulders

1. You can go 245/45/19 on all four with your 351m wheels, no problem at all. I did the equivalent setup with my winter tires and they thickened the sidewalls with associated improvement in ride.

Did the same, and agreed 100%. Here's 245/45-19 on 19x9 on stock suspension.

[PagedAtol17]

Originally Posted by Blue Angel

Did the same, and agreed 100%. Here's 245/45-19 on 19x9 on stock suspension.

Out with the old and in with the new. Thx everyone for their input and help!!! Went from stock 17s on 225/55/17 continental Conti pro contacts runflats to 351m square 19x8.5 on 245/45/19 Michelin primacy mxm4 runflats

[Blue Angel]

Congrats!!! What a huge improvement!