[Turn2inTX]

840i Gran Coupe owner in Houston here with a member question on successful non-BMW rear toe and camber settings. I, like other 8-series owners on this forum, unexpectedly ran the inner most tread of my rear 20” Goodyear ROF tires down to the cord in less than 9k miles. 4-wheel Alignment verified to be within BMW specs. I wasn’t a fan of the ROF tires and replaced all 4 with proper staggered OE 20” sized Continental tires a few weeks ago.

I mostly drive my 840 on TX state highways and want to improve future tire wear life. I purchased quality rear adjustable camber and toe arms with the plan on having a well-respected independent alignment shop adjust my rear toe and/or camber settings less aggressively than those specified by BMW. Would love to hear from any members who have tried the same and what if any final rear alignment setting recommendations, you were happy with.

[John H.]

For your driving style, sounds like a little too much negative camber. That being said, BMW does seem to set it that way. Have your tech adjust it accordingly.

RFT can be a little stiff. Conti is good choice for non-RFT. The DWS 06 is the model I would recommend. They are a great A/S tire, and perform very well in the rain. Also, treadwear rating is very high.

If available, please post your alignment sheet/results. I would like to see it.
.

[Turn2inTX]

Thanks for the feedback John. As I mentioned previously, after finding my rear ROF tires worn down to the cord on the inner tread, I had my alignment checked as it was within BMW alignment specs. After installing a new set regular Continental tires, I returned to the Alignment shop. This time I asked the tech to see how close he could get the rear camber and toe to zero. That is when I found out he couldn't do it because the OE camber and toe arms don't have much adjustment. Below are the specs I am at, but thinking I should strive for lower Toe readings to improve tire wear after reading similar Bimmer posts. I have purchased a set of adjustable rear camber and toe arms and reached out to hear from other 8-series owners who would share what they found to be acceptable readings to improve tire wear.

BMW spec Left Tire Right Tire
Camber -2.3 to -1.4 deg -1.6 deg. -1.8 deg.
Toe 0.07 to 0.27 deg 0.17 deg. 0.17 deg.

Cross camber -0.5 to + 0.5 deg. Actual 0.2
Total Toe 0.13 to 0.53 deg. Actual 0.34
Thrust Angle -0.20 to +0.20 deg. Actual 0.00

[John H.]

As per our convo, via PM, here is the official BMW alignment info on your G16 (RWD)...

[RockCrusher]

Had a similar problem with my Porsche 996 Turbo. Rear tires gone -- insides edges to the belts -- in 8K miles.

Bought new tires at another dealer and asked the tech to give the car a tire wear friendly alignment but one that would not compromise the car's superb road manners.

He was successful. The secret was less rear wheel toe. (Camber doesn't appear to affect tire wear. As a tech told me what position of the wheels/tires you see when the car is stationary is not the same position as when the car is moving down the road.)

After the alignment the rear tires lasted to 20K miles. This was *normal* tire life both with my Turbo and the Boxster I owned too. Rear tire wear across the tread surface was even.

[Turn2inTX]

Thanks for that feedback RockCrusher. I have read several posts recommending lower rear toe settings to improve rear inner tire wear. Hence is why I bought new toe arms with more adjustment. My hope was to get some actual setting numbers from 8-series owners that achieved what you did - about 20-25k miles of wear before replacing. I made a change from ROF to Continental regular tires and understand wear friendly alignment settings are next.

[Beemer5to3]

Turn2inTX Will keeping the standard suspension components and just adjusting to the maximum tolerances not help at all?

I’ve got a similar issue (840i GC sDrive), and my alignment is perfectly within BMW spec, however my left rear seems to wear its inside portion quicker. The right rear doesn’t seem too bad oddly, but it put it down to the amount of roundabouts in the UK potentially and the amount we turn right!

[RockCrusher]

Originally Posted by Beemer5to3

Turn2inTX Will keeping the standard suspension components and just adjusting to the maximum tolerances not help at all?

I’ve got a similar issue (840i GC sDrive), and my alignment is perfectly within BMW spec, however my left rear seems to wear its inside portion quicker. The right rear doesn’t seem too bad oddly, but it put it down to the amount of roundabouts in the UK potentially and the amount we turn right!

Uneven/unequal rear tire wear often arises from too heavy a foot on the accelerator pedal during turns.

Here in the US it is the right rear tire that suffers. Most turns, and the sharpest turns, are to the right.

In the UK the left rear tire would experience more wear.

[RockCrusher]

Originally Posted by Turn2inTX

Thanks for that feedback RockCrusher. I have read several posts recommending lower rear toe settings to improve rear inner tire wear. Hence is why I bought new toe arms with more adjustment. My hope was to get some actual setting numbers from 8-series owners that achieved what you did - about 20-25k miles of wear before replacing. I made a change from ROF to Continental regular tires and understand wear friendly alignment settings are next.

I would not expect new toe arms necessary to allow enough adjustment to ease up on the toe in. I'm not talking about huge changes. I don't have scans of the print out showing graphically a car's alignment but in this context the toe settings are still equal left to right but not as much. The settings are still in the green.

I do have a pic of the alignment screen from my Turbo's alignment. The final settings aren't in effect yet.

But you can see the green area allows for enough adjustment, at least in my experience both with my Turbo and my Boxster, for the tech to reduce the toe in enough to address excessive tire (inner edge) tread wear.

[Beemer5to3]

Originally Posted by RockCrusher

Uneven/unequal rear tire wear often arises from too heavy a foot on the accelerator pedal during turns.

Here in the US it is the right rear tire that suffers. Most turns, and the sharpest turns, are to the right.

In the UK the left rear tire would experience more wear.

Thanks - seems to make sense. These are my measurements, which do suggest the rear left is carrying more toe in vs. the right? In reality, I’ve no idea as to what difference this would make but could be a factor?

[RockCrusher]

Originally Posted by Beemer5to3

Thanks - seems to make sense. These are my measurements, which do suggest the rear left is carrying more toe in vs. the right? In reality, I’ve no idea as to what difference this would make but could be a factor?

My best advice would be to discuss the numbers with the tech.

I don't know what the tolerances are for the M8 but I'd like to see the toe in of both rear wheels closer. The front wheel toe in numbers are closer. Why aren't the rear toe in numbers closer?

I'm thinking less total toe in is better but after I got the car aligned after new rear tires fitted the car felt fine and tire life was good I don't recall the alignment numbers. The tech assured me he would give the car a tire wear friendly alignment and that's what he did.