New tires (rear) seem hard to come by

I ordered new tires in Nov 2016 from Tire Rack. Fronts in stock but estimated delivery for rears was Jan, then Feb, and now is March 15. My rears were a little thin on the tread when I ordered and I was looking to have the car a little safer in rain. Now it has gotten to where I make it a point not to drive it in the rain. We do have another car so it is not critical. But sheesh........ :?

There is another thread in this section. Read there as the dealers seem to have received a replacemennt from bridgestone.

Had my rear tyres replaced recently at my local dealer for £139 each all in.

I think it took the dealership about a day to get them in.

I ordered new rear tires a few months back. Called my local tire shop today and they finally found a few so should have them next week. Ended up ordered front tires too since they are near the threshold and my lease isn't up until October. The wear on these tires is TERRIBLE! I've taken corners easy since I've had the car because I didn't want to replace them at the end of my 2 year lease but that won't be possible. I can (somewhat) understand the wear on the rear tires from all the torque, although I'm still disappointed that the right rear is almost bald after 18k miles, but the fronts should still have plenty of tread. Wish there were a there options for summer or all season tires.

Other places I've checked are getting more of these tires in stock now.

brorob said:

I ordered new rear tires a few months back. Called my local tire shop today and they finally found a few so should have them next week. Ended up ordered front tires too since they are near the threshold and my lease isn't up until October. The wear on these tires is TERRIBLE! I've taken corners easy since I've had the car because I didn't want to replace them at the end of my 2 year lease but that won't be possible. I can (somewhat) understand the wear on the rear tires from all the torque, although I'm still disappointed that the right rear is almost bald after 18k miles, but the fronts should still have plenty of tread. Wish there were a there options for summer or all season tires.

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Wow, 18k miles out of the rears is pretty poor. I've had mine changed after 29k miles. I know that others on this forum got similar mileages on their rears. My fronts have another 10k miles in them, I'd say.

What is the tire wear pattern? Worn down the center, worn on the inner or outer tread? Is anyone having the car re-aligned? In our shop on the e39's our customers were going through the Mich. Sports in less that 20k. miles. They were wearing the inner 2 inches bald yet the rest of the tread had probably another 15+K miles left. Looking at BMW's rear alignment specification, they had a very aggressive toe-in called for. This combined with the Mich Sport being a summer high performance tire was killing the tires. We took some of the rear toe-in spec out during realignment. This solved the tire wear issue with no compromise to the handling. I have not taken delivery of our I3 yet but it will be one of the first things I plan on looking at. Does anyone have any insight to the thought?
Thanks,
Road Jager

RoadJager said:

I have not taken delivery of our I3 yet but [alignment] will be one of the first things I plan on looking at. Does anyone have any insight to the thought?

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In general, those i3 drivers who really enjoy the i3's instant torque wear out their rear tires faster than those who don't express their torque enjoyment so frequently. For some reason, the right rear tire wears faster (less weight so less traction on the passenger side, motor torque unloads the passenger side tire so that it has less traction??).

Also, the i3's aggressive regen is applied to the rear wheels, so that increases their wear rate relative to ICE vehicles in which engine braking isn't nearly as strong as the i3's regen, and relative to the front tires unless one frequently corners aggressively or drives on windy roads.

When our first set of tires wears out, I might have an alignment shop set the front and rear toe and the rear camber to their lower limits in BMW's spec. If the current toe is significant, reducing it could decrease rolling resistance enough to increase range a bit and reduce the tire wear rate.

Please post what you learn about the alignment on your i3.

Good point on the regen affecting this also, Art.

Just measured my tires, mileage is currently 18,445.

Left rear: inner = 1/32, outer = 4/32
Right rear: inner = <1/32, outer = <4/32
Both fronts: inner = 3/32, outer = 5/32

Anxiously awaiting my local tire shop to call, new tires were supposed to be in today.

RoadJager said:

What is the tire wear pattern? Worn down the center, worn on the inner or outer tread? Is anyone having the car re-aligned? In our shop on the e39's our customers were going through the Mich. Sports in less that 20k. miles. They were wearing the inner 2 inches bald yet the rest of the tread had probably another 15+K miles left. Looking at BMW's rear alignment specification, they had a very aggressive toe-in called for. This combined with the Mich Sport being a summer high performance tire was killing the tires. We took some of the rear toe-in spec out during realignment. This solved the tire wear issue with no compromise to the handling. I have not taken delivery of our I3 yet but it will be one of the first things I plan on looking at. Does anyone have any insight to the thought?
Thanks,
Road Jager

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After finally getting my new tires yesterday, I'm not sure how much of the wear is related to the toe-in adjustment on the car. Visually it looked like the inner grooves of the tire had less tread depth than the outer grooves, so I confirmed this by measuring the tread depths. See pics below for measurements.

Not sure why Bridgestone does this, maybe there's a reason? This would seem to mean that when a BMW dealership measures the tires at lease end, customers are automatically losing 3/32 tread by tire design if the dealer is using the inner tread depth for their evaluation of whether the tires need to be replaced. This also aligns with the measurements of my currently installed worn down tires. I wonder how many people have been screwed by the dealer at lease end because of this design. 7/32 tread depth for a brand new tire doesn't seem acceptable to me, unless there's some logical reason for it.

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Not sure is this is BMW's reasoning, but the deeper the tread, the more it squirms under load, and thus, there's a measurable increase in drag. The shape of the sipes and blocks can help, but not eliminate that effect, so it's a tradeoff.

Still waiting on new rears with no firm delivery date yet. Adding insult to injury, just discovered right front tire with large sidewall bulge. Pretty sure a pothole did it. Very hard to avoid them here in Honolulu area with all the recent rains creating hundreds of new ones in addition to the crappy roads. Told Tirerack to send out the fronts they have been holding waiting for the rears. Wish there was some way to get Bridgestone to up the frequency of their production of these tires. Wife not happy since this her car. :evil:

Torresr001 said:

Still waiting on new rears with no firm delivery date yet.

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There have been reports that the new 20" rear tire that has a higher load rating, 175/55 R20 89Q, is available while the old lower load rating tire, 175/55 R20 85Q, remains unavailable. There's no problem using the higher load rating tires.

Torresr001 said:

Adding insult to injury, just discovered right front tire with large sidewall bulge. Pretty sure a pothole did it. Very hard to avoid them here in Honolulu area with all the recent rains creating hundreds of new ones in addition to the crappy roads.

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Our Honolulu i3 has 19" wheels that I keep inflated at 10 psi over BMW's recommended inflation pressures in hopes of protecting our tires and wheels from pothole damage. So far, this has worked. The ride is a bit rougher and there might be slightly less traction, but the range might be slightly greater, so I'm willing to accept the trade-offs.

Had my new front tires installed at Capitol tire and service near Costco Waipio. They did four wheel alignment as well. It made a noticeable difference in the handling and feel of the car-not quite as squirrelly. Still waiting on new rears - now due in 17 April. I am impressed with Capitol - honest, quick, efficient clean shop. Asked if overinflating tires might be helpful in the future and general manager Philip said he did not recommend as useful. Food for thought.

Increasing the inflation pressure might be useful if you always carry a full load in the vehicle, otherwise, making the tire stiffer also means making it more susceptible to damage when going over a bump. You can damage a tire by too low and too high pressure. Too low, you might get excessive flexing and not only damage the tire, but the wheel as well. To high, it might not survive a significant bump. Either one can transmit a major load to the wheel, and damage it in the process.