[skilz4u2nv]

Looking to replace tires on my M850

Found threads that talk about making them a little wider
Found threads that talk about making them a little taller
Could not find a thread that talks about doing them both together!

Currently on:
245/35/20 front
275/30/20 rear

I would like a little more meat on the tire as I drive through NYC potholes alot and I also like the idea of making them slightly wider.

Thinking of going to:
255/40/20 front
285/35/20 rear

Is anyone currently on that setup and can vouch its feasible?

[autobahnscott]

Since you are in New York are you considering All-Season tires?

[skilz4u2nv]

Originally Posted by autobahnscott

Since you are in New York are you considering All-Season tires?

Yep, When I bought the car it came with summer tires.
Definitely can't drive with those in the Northeast winters.

[Moopai]

Any specific reason why you're going with 40 front and 35 back when you currently have 35 front 30 back? I can understand with a bit more rubber you could protect your wheels especially since you are living in NY but I always feel the higher the rubber, the less sporty the tire will look! I'm thinking of doing the same set up but I will go 35 front and 30 back.

Originally Posted by skilz4u2nv

Looking to replace tires on my M850

Found threads that talk about making them a little wider
Found threads that talk about making them a little taller
Could not find a thread that talks about doing them both together!

Currently on:
245/35/20 front
275/30/20 rear

I would like a little more meat on the tire as I drive through NYC potholes alot and I also like the idea of making them slightly wider.

Thinking of going to:
255/40/20 front
285/35/20 rear

Is anyone currently on that setup and can vouch its feasible?

[BMWGUYinCO]

For what its worth, I can't recommend highly enough tires from Vredestein.

I bought these all seasons for my M850 Convertible and they have been outstanding, in terms of summer grip, rain/light snow traction, etc.

But let me tell you one more story. I hit a giant pothole with the right front so hard it severely bent the rim. Instead of a blowout though, the Vredestein tire developed a sidewall bulge. I was about 45 miles from home and the speed on the route was above 65 mph. The tire held.

When I brought it back to my tire center for replacement, the crew couldn't believe how well it had held together. My treadwear is great and they are very quiet and smooth running. I liked them so much I bought a set for my wife's X3 M40 and take every chance I get to recommend.

Not sure it comes in the optional sizes you want, but you should take a look at them. Here is a review Tire Rack did against some heavy hitters: https://www.tirerack.com/tires/tests...y.jsp?ttid=280

[skilz4u2nv]

Originally Posted by Moopai

Any specific reason why you're going with 40 front and 35 back when you currently have 35 front 30 back? I can understand with a bit more rubber you could protect your wheels especially since you are living in NY but I always feel the higher the rubber, the less sporty the tire will look! I'm thinking of doing the same set up but I will go 35 front and 30 back.

Strictly to give me a little more comfort as i smash into a pothole that seemingly comes out of nowhere here!
But I have the same internal struggle as you in that the 35F/30B are more sporty looking than the 40F/35B

I actually did this with my old 6series and it worked well plus it filled out the wheel well a little bit more

[Accentu8]

40 front and 35 rear fill out the wheel well so nicely that the car looks lowered…but not too much. I love the Continental Contact 06+ A/S I chose. Great traction, wet or dry, great handling, performance and very quiet and comfortable.

Pic 1 before, pic 2 after.

[Draxxas]

Originally Posted by Accentu8

40 front and 35 rear fill out the wheel well so nicely that the car looks lowered…but not too much. I love the Continental Contact 06+ A/S I chose. Great traction, wet or dry, great handling, performance and very quiet and comfortable.

Pic 1 before, pic 2 after.

Thinking about exact (tires , size) with my 850.
How far did the change affect Speedo?

[Velvet Fog]

Originally Posted by Accentu8

40 front and 35 rear fill out the wheel well so nicely that the car looks lowered…but not too much. I love the Continental Contact 06+ A/S I chose. Great traction, wet or dry, great handling, performance and very quiet and comfortable.

Pic 1 before, pic 2 after.

Like how it looks with a little more rubber, but I was driving an F150 before on 285/65s.

That's the exact set up I'll be getting after the stock Goodyear run flats wear out.

[skilz4u2nv]

Love it, that 40F and 35R do fill it up nice!

Now just need to confirm if i can do that and couple it with 255F and 285R or if that is just too much of a change for the xdrive

[Draxxas]

Originally Posted by skilz4u2nv

Love it, that 40F and 35R do fill it up nice!

Now just need to confirm if i can do that and couple it with 255F and 285R or if that is just too much of a change for the xdrive

You'll be fine. Total diameter between front and rear is all your concerned with here.

[Van_bimmer]

Following. Looking to do the same 40F and 35R to help fill out and soften the pothole shudders a bit, let us know how it works out! ��

[skilz4u2nv]

Just ordered the tires and they called me up right away telling me that they wont fit because it will rub and to stick with stock sizes

Any truth to that or is it some scare tactic?

[Moopai]

If you stick to 35F/30R, you may not have any issues.

Originally Posted by skilz4u2nv

Just ordered the tires and they called me up right away telling me that they wont fit because it will rub and to stick with stock sizes

Any truth to that or is it some scare tactic?

[snowbimmer]

Alpinas run the taller profile. Plus several others on this forum

Accentu8 ??

[skilz4u2nv]

Originally Posted by snowbimmer

Alpinas run the taller profile. Plus several others on this forum

Accentu8 ??

Great point, and the Alpina I believe is built on the m850 so in theory should all work out

[ElloM8]

Originally Posted by skilz4u2nv

Just ordered the tires and they called me up right away telling me that they wont fit because it will rub and to stick with stock sizes

Any truth to that or is it some scare tactic?

Bull S**T! I run 295/35/20 on the rear and 255/40/20 on the front. I also have a +27 offset on the front and a +42 on the rear. I have NO rubbing. That includes when the car is loaded down with crap. It throws the speed off by about 2mph at 70. The ride is fantastic.

[snowbimmer]

Originally Posted by ElloM8

Bull S**T! I run 295/35/20 on the rear and 255/40/20 on the front. I also have a +27 offset on the front and a +42 on the rear. I have NO rubbing. That includes when the car is loaded down with crap. It throws the speed off by about 2mph at 70. The ride is fantastic.

This is where I wanted to go when I went wider (255 F & 295 R), but chickened out and stayed at OEM height - a lot of it due to my dealer being adamantly opposed to going up a profile. You, and several others here keep proving that by just keeping the front and back heights the same you won't screw up the x-drive. I had the option of 32 and 25 front offset - I went with the 32 but felt the 25 would have still been ok. I'm at a 45 in the year, so you're out an additional 3mm.

BTW, I think being off by 2 mph would actually put your car at the real MPH - due to BMW speedos understating the speed by about 2 mph. (If I'm doing the math right. Math is hard.)

Looks great.

[Moopai]

Is there a reason why you went 40F/35R and not 35F/R?
What brand of tires do you have? Are they Run Flats?

Originally Posted by ElloM8

Bull S**T! I run 295/35/20 on the rear and
255/40/20 on the front. I also have a +27 offset on the front and a +42 on the rear. I have NO rubbing. That includes when the car is loaded down with crap. It throws the speed off by about 2mph at 70. The ride is fantastic.

[Moopai]

Any idea why BMW is using a lower profile tires on the M850 vs M8C which has 35s F/R?

[snowbimmer]

Originally Posted by Moopai

Is there a reason why you went 40F/35R and not 35F/R?
What brand of tires do you have? Are they Run Flats?

Originally Posted by Moopai

Any idea why BMW is using a lower profile tires on the M850 vs M8C which has 35s F/R?

You gotta go 40/35 (OEM height is 35/30) to keep the diameters in line because the front tires are so effing narrow (245 OEM for the fronts). The OEM 245/35/20 and 275/30/20 will have about 1/4" difference (front bigger). The 255/35/20 and 295/30/20 will narrow that gap to about 1/16"

M5s and M8s run 275/285, so they can run a 35 profile all the way around.

I don't know why they would put such small tires (M850) on such a big effing car. I can see where they want to keep the M8 special, but when you strip out all the special stuff in an M8 you still have an M850 that is just as long, just as heavy and almost as fast. Makes no sense, but that's just me. Physics doesn't take a vacation. Ever.

And the low profile tires make the ride less compliant and the car more susceptible to bent rims - which I did to my relatively new Vossens fairly quickly.

[ElloM8]

Originally Posted by Moopai

Is there a reason why you went 40F/35R and not 35F/R?
What brand of tires do you have? Are they Run Flats?

This is the M850i. It's full time AWD so the tires have very stick requirements regarding the circumference front to back. Not as big a deal on the M8 since you can run in RWD unit you need AWD. They are Lexani tires and they are not run flats. I HATE run flat tires. They manage to be more ridged then my Summer tire set up that requires 45PSI to protect the 22" wheel.