Tesla 940
Member
Everyone's comments / opinions are great! Makes me want to burn up my tires so I can try something new. At the rate I drive it will be another 6 - 12 months.
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Tip: MPSS are fantastic dry/wet tires, but they are downright dangerous on snow/ice. Don't be tempted to try it!
I was recently told by a tire tech who went to one of Michelin's training sessions that the compound they use on the MPSS can sustain permanent damage just by storing it much below freezing whether they're mounted or not. He said you're OK into the 20's (F) but not much below that. I've seen the warnings before but assumed it only applied if the tires were mounted.
Fortunately I never let them get that cold. I was late swapping them off my G37 this fall, and the first time it snowed I ended up going sideways at a mere 30 kph :scared:. So I swapped them out immediately! They were stored indoors, but have now been sold since I traded the G37.
I believe the Yokohama A048's have the same limitation. I store them in the basement over the winter (except the rears... which are bald anyway).
> the MPSS can sustain permanent damage just by storing it much below freezing whether they're mounted or not. [hcsharp]
Tire store never warned me about this, plus I've never heard of this concept. I would have stored them in bags in the house had I known. Outdoors minimum hit -15*F (-26*C) for a couple days, a mild winter. So have these tires turned to bakelite or, in the other direction, to mush? What failure mode is likely to rear its ugly head? Can't wait to find out and return to Discount Tire.
I was thinking the other day that it might make sense simply to run the Yoko snows all year round and replace fresh every November. This since they don't exhibit any 'snow tire' characteristics in my style of driving. But can they withstand summer warmth? Yoko iG20s all around: no text warning on tape except 'winter'. Ok, not such a good idea.
--
Tire store never warned me about this, plus I've never heard of this concept. I would have stored them in bags in the house had I known. Outdoors minimum hit -15*F (-26*C) for a couple days, a mild winter. So have these tires turned to bakelite or, in the other direction, to mush? What failure mode is likely to rear its ugly head? Can't wait to find out and return to Discount Tire.
I was thinking the other day that it might make sense simply to run the Yoko snows all year round and replace fresh every November. This since they don't exhibit any 'snow tire' characteristics in my style of driving. But can they withstand summer warmth? Yoko iG20s all around: no text warning on tape except 'winter'. Ok, not such a good idea.
--
jordanthompson
2018 P100D Model X
Buyer Beware!!!
235/45ZR17 Michelin Pilot Sport A/S
I got these tires installed a few months ago and just recently started getting Drive Train Fault indications. I called Tesla and they sent Byron from Miami because they could't get the logs from the car (and never asked me to pull them.) The first thing Byron noticed were the tires. He didn't say anything, but waited until the logs confirmed his suspicions. Sure enough, he said this is a common problem up north because snow tires are generally larger than normal sized tires. The DTF was because of the different sized tire(!) and put different stresses on the drive train. He said to just ignore the problem.
While Byron was working on the car:
He reset the OVMS (to remedy the car not being able to communicate its logs) by pulling the two plugs under the passenger seat and waiting a few minutes.
He also discovered the left rear sending unit on the tire needs to be replaced, which is why the TPMS was not working either (is there any way to disable the TPMS?)
235/45ZR17 Michelin Pilot Sport A/S
I got these tires installed a few months ago and just recently started getting Drive Train Fault indications. I called Tesla and they sent Byron from Miami because they could't get the logs from the car (and never asked me to pull them.) The first thing Byron noticed were the tires. He didn't say anything, but waited until the logs confirmed his suspicions. Sure enough, he said this is a common problem up north because snow tires are generally larger than normal sized tires. The DTF was because of the different sized tire(!) and put different stresses on the drive train. He said to just ignore the problem.
While Byron was working on the car:
He reset the OVMS (to remedy the car not being able to communicate its logs) by pulling the two plugs under the passenger seat and waiting a few minutes.
He also discovered the left rear sending unit on the tire needs to be replaced, which is why the TPMS was not working either (is there any way to disable the TPMS?)
Last edited:
strider
Active Member
Which tires are "these tires"? MPSS? Did you do the new-tire learn feature (not sure if that's a 2.5-only feature)?
jordanthompson
2018 P100D Model X
Sorry about not being specific - I added the model to my comment. I did do the new-tire learn feature (I have a 2.0) and it was successful. This only affects the TPMS, as far as I understand. The problem with the drive train fault cannot be corrected (again, as I understand) until I put regular-sized tires back on the car.
The new tire learning feature has nothing to do with TPMS. I would try re-learning the tires again. I had a similar warning, not a fault, and it went away when I re-learned the tires.
Are you having traction control problems? Are you getting full regen?
jordanthompson
2018 P100D Model X
strider
Active Member
jordanthompson
2018 P100D Model X
OK I went through the motions of relearning the tires and all seems well with the world (still getting a TPMS light, but I know one of the sending units is bad.) Of course, this was working great for a month or two before going nuts, but if all it takes is to relearn the tires, I am golden! hcsharp, thanks very much for the suggestion to try re-learning! I am going to forward this info to Tesla Miami as apparently it didn't occur to them either.
strider
Active Member
I realize that but I assumed this could be related to rolling circumference or something and figured the MPSS's would have similar dimensions as the A/S's so thought I would chime in.
Got it. sorry.
Yeah, you would think they would be pretty close to the same diameter. When I look at his pics where he wants to put his hands in the wheel well, it seems like I have more room with the MPSS. Can't really tell for sure.
jordanthompson
2018 P100D Model X
So much for that :-( I just got the dreaded fault again :-( I guess I'll just keep re-learning the tires until they wear out...
JohnnyLounge21
Member
driver_ev - almost 4 months later. Got another update for us? Anxious to see if we've cracked the "need to buy new tires every 8K miles" code! And by you getting to 10K and beyond - wondering how the Michelins are still holding up!
driver_EV
Member
Sorry I have been off TMC for a while. Jordan, I see you got the +size tires like I have on my Roadster. The fault probably results from the slight change in revolutions per mile due to the 1/4inch increase in overall tire radius. The computer noticed the rear tires are turning slightly slower in relation to the front tires. If this is a concern, (I have really enjoyed the 235 size on my car) the Mich can be sized at stock 225 to eliminate that difference.
- - - Updated - - -
I will post pictures of my tires showing they are now pretty worn, at near 22k miles on the car. I have ordered the second pair of Mich tires. Since I mostly drive the Model S, the Roadster gets only local driving. My next change after replacing the worn rear tires will be to try + size on fronts as well. The purpose for trying this is mainly to see if it allows the roadster drive computer to be happier, since the slight increase in tire radius for the front tires may closely match the slight radius increase of the rear tires.
BTW, I am trying the Pilot Sport AS3 in the 235 size. Specs are pretty similar to the last pair.
Last edited:
driver_EV
Member
Slim pickin's on plus size for front of Roadster. When I try these, I will crank up the front air pressure to try and preserve handling taking turns that I currently enjoy.
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+7000+A%2FS&partnum=855HR67000
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+7000+A%2FS&partnum=855HR67000
driver_EV
Member
OK, at 21,983miles, rear MICH "PilotSport plus 235/45R17" tires are WORN OUT, and were just replaced (second set of Michelin, but trying NEW "PilotSport A/S 3" tires now).
OLD:
Note: directional tread design of these tires!
Just to review history:
Issues at less than 8k miles on 2011 Roadster Sport (with factory advised sport/performance settings on adjustable suspension):
1) Rear tires (original Yoko) worn, already require replacement on my daily driver.
2) Not thrilled with tires wearing this quickly, and being kind-of expensive to replace.
3) Car has under-steer behavior that not as fun as I would like.
Decision made to select, and try out a different pair of tires for the back of the Roadster.
http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Pilot+Sport+A%2FS+Plus&partnum=345YR7PSAS
* looking to deal with under-steer (and liking some adventure), I increased physical tire size slightly from 225/45 to 235/45.
The change in size and other physical properties of the rear tires resulted in understeer being no longer an issue!
, though 40psi is too low, 45psi seems to keep the car from getting too wild. (disclaimer: caution advised at high speeds, car is not for racing with these tires)
* Other two issues improved as well, since these tires cost less, and have higher treadwear properties.
* Additional benefit from these specific tires is the car ride is smoother over bumps, and tires are more quiet.
- - - Updated - - -
Negative results?:
* In summer Interstate hwy driving, Roadster display reports a warning "over pressure" in rear tires as they get warmed up with high speed driving. This happens because the original YOKO tires have lower pressure rating than the MICH do. (this situation is not a real safety issue of any kind.) The proper thing to do would be to calibrate the Roadster TPMS to represent the higher Michelin tire pressure specs. My solution at the time was to reduce the tire pressure by 1psi when this alarm happened. Warning issue was solved for that trip.
* Tesla has very tight "wheel speed" sensing as part of traction control, stability, safety features in the car. It expects the tire physical size to exist within tight limits, and power-train faults are issued by the computer software based on the larger tires turning slightly slower than nominal in comparison to the (unpowered) front tires. Some Roadsters turn on a "fault indicator warning" with the larger tires on the back, and presumably the software may not deliver nominal performance (power), or anti-lock braking, traction control features of the sophisticated Tesla software operation, may be less than what is expected. (traction limit light may illuminate more frequently than normal over bumps, gravel surface, etc.) May be more of an issue for the earlier production Roadsters.
From my experience, the car has worked fine, seems to have normal operation, loads of power, and stability control seems to be working just fine. So for me, these are minor technical glitches, and will try to address them, but they are not deal breakers.
I have been very satisfied and happy with these tires on the back of the Roadster, and definitely would buy them again, except, I see the new A/S 3 from Michelin, and am trying a pair of them now in the same non-spec size 235/45.
Out with the old, and in with the NEW!:
Note: the new tires have asymmetrical design. Unlike the last pair, these are non directional, but must be oriented with the correct side facing out on the car.
Initial test drive is good, but will need to get some miles on the tires, before reporting further.
- - - Updated - - -
Pushing a little beyond safety, the oversize Mich tires on the back of the Roadster provided 21,983 - 7,760 = 14,223 miles.
Perhaps should have replaced them earlier, but ~14,000 miles on rear tires of the Roadster is a win for me.
I drive in performance mode, and enjoy spirited driving typically 0-50 mph, so I do not go easy on the tires. It is very possible to get more miles from them.
- - - Updated - - -
The adventure continues: Now bigger front tires too:
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+7000+A%2FS&partnum=855HR67000
Continuing to use All Season Performance tires as preferred type, only the SP Sport 7000 A/S is available in the size 185/55R16.
Of course, clearance for the larger tires is a worry, and it is more difficult to judge for front wheels. (one way to find out)
BTW: I am still running the original Yoko's on the front of the car. They still have fairly deep tread. They look like around 25% tread left, but I will replace them soon with a pair of plus size all-season tires.
It will be very interesting to see if this helps with the wheel speed difference that is making the drive computer unhappy. If I am right, that little glitch might get fixed!
To share what I am thinking with the drive computer fault, and why I think it may be solved with new front tires:
* Expectation is that the drive computer uses the front wheel speed as a reference to judge the speed of the rear (driven) wheels.
* It has expectations (limits) on what it wants to see as a difference in wheel speed when the car is driven, and since the front and rear wheels are of a different radial size, the front wheels will be turning at a different speed in relation to the rear, that difference has a nominal value tolerance, if the difference is too great (due to installing larger tires on back) the computer software logs errors and may signal a fault.
Using the TireRack listed specs of the original Yoko tires, and the +size Mich to calculate the difference this causes:
Rear 225 size Yoko tires = 835 rev per mile
Rear 235 size Mich tires = 821 rev per mile (makes sense since the radius is ~1/4" more on these tires)
So, based on this, the speed signal for the rear wheels would be ~98.3% of nominal when using the 235/45 size Michelins, or ~1.7% less than what the computer expects based on reference to the front wheel speed. (with front tires being still at 100% spec size)
My plan is to try and make a similar adjustment to the front tires, and replicate the wheel speed difference in the front so the computer will see less of a difference. Perhaps the difference will fall within nominal specs in this way.
Front 175/55 size Yoko tires = 882 rev per mile
Front 185/55 size Dunlop tires = 863 rev per mile
This would result in new front tires providing ~97.8% of nominal or 2.2% slower than what the computer would have seen with the original size tires.
So looking at it this way, instead of the rear wheels turning 1.7% slower than expected in non-slip conditions (by changing only the size of the rear tires), the difference looks closer to ~.5% difference by changing size of both front and rear tires.
Another way:
By looking just at the difference in nominal wheel revs per mile (882 front, and 835 rear) shows the computer would expect the front wheel speed to be ~5.6% faster than the rear (non-slip). In other words, the computer wants to see that 5.6%
By increasing only the rear tires, the difference is more like the front is 7.4% faster than the rear wheels.
If instead, I also change to the +size on the front tires, the resulting front/rear revs per mile are more in proportion @~5.1%.
Front Dunlop = 863 rev per mile
Rear Mich = 821 rev per mile
In short, what I am saying is the computer wants to see a 5.6% difference, It may be happy enough with 5.1%.
jordanthompson you may benefit if this works with the faults you are getting on the + size rears.
OLD:
Note: directional tread design of these tires!
Just to review history:
Issues at less than 8k miles on 2011 Roadster Sport (with factory advised sport/performance settings on adjustable suspension):
1) Rear tires (original Yoko) worn, already require replacement on my daily driver.
2) Not thrilled with tires wearing this quickly, and being kind-of expensive to replace.
3) Car has under-steer behavior that not as fun as I would like.
Decision made to select, and try out a different pair of tires for the back of the Roadster.
http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Pilot+Sport+A%2FS+Plus&partnum=345YR7PSAS
* looking to deal with under-steer (and liking some adventure), I increased physical tire size slightly from 225/45 to 235/45.
The change in size and other physical properties of the rear tires resulted in understeer being no longer an issue!
, though 40psi is too low, 45psi seems to keep the car from getting too wild. (disclaimer: caution advised at high speeds, car is not for racing with these tires) * Other two issues improved as well, since these tires cost less, and have higher treadwear properties.
* Additional benefit from these specific tires is the car ride is smoother over bumps, and tires are more quiet.
- - - Updated - - -
Negative results?:
* In summer Interstate hwy driving, Roadster display reports a warning "over pressure" in rear tires as they get warmed up with high speed driving. This happens because the original YOKO tires have lower pressure rating than the MICH do. (this situation is not a real safety issue of any kind.) The proper thing to do would be to calibrate the Roadster TPMS to represent the higher Michelin tire pressure specs. My solution at the time was to reduce the tire pressure by 1psi when this alarm happened. Warning issue was solved for that trip.
* Tesla has very tight "wheel speed" sensing as part of traction control, stability, safety features in the car. It expects the tire physical size to exist within tight limits, and power-train faults are issued by the computer software based on the larger tires turning slightly slower than nominal in comparison to the (unpowered) front tires. Some Roadsters turn on a "fault indicator warning" with the larger tires on the back, and presumably the software may not deliver nominal performance (power), or anti-lock braking, traction control features of the sophisticated Tesla software operation, may be less than what is expected. (traction limit light may illuminate more frequently than normal over bumps, gravel surface, etc.) May be more of an issue for the earlier production Roadsters.
From my experience, the car has worked fine, seems to have normal operation, loads of power, and stability control seems to be working just fine. So for me, these are minor technical glitches, and will try to address them, but they are not deal breakers.
I have been very satisfied and happy with these tires on the back of the Roadster, and definitely would buy them again, except, I see the new A/S 3 from Michelin, and am trying a pair of them now in the same non-spec size 235/45.
Out with the old, and in with the NEW!:
Note: the new tires have asymmetrical design. Unlike the last pair, these are non directional, but must be oriented with the correct side facing out on the car.
Initial test drive is good, but will need to get some miles on the tires, before reporting further.
- - - Updated - - -
Pushing a little beyond safety, the oversize Mich tires on the back of the Roadster provided 21,983 - 7,760 = 14,223 miles.
Perhaps should have replaced them earlier, but ~14,000 miles on rear tires of the Roadster is a win for me.
I drive in performance mode, and enjoy spirited driving typically 0-50 mph, so I do not go easy on the tires. It is very possible to get more miles from them.
- - - Updated - - -
The adventure continues: Now bigger front tires too:
http://www.tirerack.com/tires/tires.jsp?tireMake=Dunlop&tireModel=SP+Sport+7000+A%2FS&partnum=855HR67000
Continuing to use All Season Performance tires as preferred type, only the SP Sport 7000 A/S is available in the size 185/55R16.
Of course, clearance for the larger tires is a worry, and it is more difficult to judge for front wheels. (one way to find out)
BTW: I am still running the original Yoko's on the front of the car. They still have fairly deep tread. They look like around 25% tread left, but I will replace them soon with a pair of plus size all-season tires.
It will be very interesting to see if this helps with the wheel speed difference that is making the drive computer unhappy. If I am right, that little glitch might get fixed!
To share what I am thinking with the drive computer fault, and why I think it may be solved with new front tires:
* Expectation is that the drive computer uses the front wheel speed as a reference to judge the speed of the rear (driven) wheels.
* It has expectations (limits) on what it wants to see as a difference in wheel speed when the car is driven, and since the front and rear wheels are of a different radial size, the front wheels will be turning at a different speed in relation to the rear, that difference has a nominal value tolerance, if the difference is too great (due to installing larger tires on back) the computer software logs errors and may signal a fault.
Using the TireRack listed specs of the original Yoko tires, and the +size Mich to calculate the difference this causes:
Rear 225 size Yoko tires = 835 rev per mile
Rear 235 size Mich tires = 821 rev per mile (makes sense since the radius is ~1/4" more on these tires)
So, based on this, the speed signal for the rear wheels would be ~98.3% of nominal when using the 235/45 size Michelins, or ~1.7% less than what the computer expects based on reference to the front wheel speed. (with front tires being still at 100% spec size)
My plan is to try and make a similar adjustment to the front tires, and replicate the wheel speed difference in the front so the computer will see less of a difference. Perhaps the difference will fall within nominal specs in this way.
Front 175/55 size Yoko tires = 882 rev per mile
Front 185/55 size Dunlop tires = 863 rev per mile
This would result in new front tires providing ~97.8% of nominal or 2.2% slower than what the computer would have seen with the original size tires.
So looking at it this way, instead of the rear wheels turning 1.7% slower than expected in non-slip conditions (by changing only the size of the rear tires), the difference looks closer to ~.5% difference by changing size of both front and rear tires.
Another way:
By looking just at the difference in nominal wheel revs per mile (882 front, and 835 rear) shows the computer would expect the front wheel speed to be ~5.6% faster than the rear (non-slip). In other words, the computer wants to see that 5.6%
By increasing only the rear tires, the difference is more like the front is 7.4% faster than the rear wheels.
If instead, I also change to the +size on the front tires, the resulting front/rear revs per mile are more in proportion @~5.1%.
Front Dunlop = 863 rev per mile
Rear Mich = 821 rev per mile
In short, what I am saying is the computer wants to see a 5.6% difference, It may be happy enough with 5.1%.
jordanthompson you may benefit if this works with the faults you are getting on the + size rears.
Last edited:
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