7 ms·

Sounds like a safety critical bug. Rotating tires and replacing them asymmetrically (for example, after a tire explosion for me) is regular practice. If a small

by yholio 6y ago

Sounds like a safety critical bug. Rotating tires and replacing them asymmetrically (for example, after a tire explosion for me) is regular practice. If a small difference in wear disables critical safety systems and engages them in inappropriate circumstances, this can lead to deaths. It seems simple enough to detect that, on a straight road with the steering wheel balanced, one of the wheels makes more rotations on average; then you calibrate the algorithm based on that. Sounds like a bug in this very algorithm, or maybe some hardware defect on your specific vehicle (i.e a sensor) that interferes with it.

aidenn0 6y ago
Many AWD cars require replacing tires in sets in the manual
- ComputerGuru 6y ago
  As a long-time owner of AWD performance vehicles (Midwest for you, possible snow eight months of the year!) I can assure that whether or not you replace your tires four, two, or even just one at a time, there are absolutely zero visible/immediately tangible repercussions and the issue described with the Tesla is absolutely not normal even under those circumstances. As for the long term ramifications, you’ll definitely see increased wear/camber on the opposing tire(a) and I’ve read it could theoretically cause issues with the diff, but I find that extremely hard to believe at least for the cats I’ve driven, because the front:back power ratio is dynamically recalculated and changed continuously depending on driving conditions. If it were 4WD rather than AWD, that might be the case though.
  - o-__-o 6y ago
    Okay here is anecdotal experience. I had a set of treads on my rear tire at 15/32 while the fronts where at 9/32. Viscous coupled AWD with traction control via four-wheel braking. I first noticed something was up when the car would launch rather quickly. I added an odb-2 reader and saw my AWD clutch was engaging a lot. Thought this was by design due to my heavy foot. Then the clunking started. The AWD would rather stay engaged which puts strain on the transmission to shift harder. Over time this showed up as increased transmission temperatures. My transmission is sensitive to heat but has a poor design which makes any heat a very big deal. At about the same time I was researching new wheels and determined I could fit 9” wide tires in the rear vs 8.5” in the front. A staggered wheel set would give me more rear wheel power bias, but the closest I could get in tire size was still almost .5% larger in diameter. In all my research it turns out you need tires of the same size within 3/16 wear of each other to avoid non-full time AWD transmissions from doing dumb things like my car does. You see, the AWD clutch simply engages a power transfer unit and then depends on ABS to control power sent by the differential to individual wheels. That system needs to recalibrate itself regularly and it does this when the clutch disengages. When it doesn’t, all sorts of warnings are tripped (in my car I went down 6 floors of a spiraling parking garage exit at 15-20mph and at the 2nd floor a “service stabili-trak” icon appeared on my dashboard) In cars with a well designed AWD system this will not happen.. but most cars are not designed to engage in AWD for prolonged periods of time and are really there as a beefed up version of traction control. For instance my Torsen Quattro AWD Audi had full time AWD and never had this problem nor would a Nissan GT-R. But for that fancy Lexus or Hyundai AWD, you may want to make sure you stick to the recommended tire rotation schedule To end my story, I was at the service center and they mentioned I should get my transmission checked out by the bigger repair bay because of the clunking. I suggested it may be the wear of the tires and they agreed to see if that solved the problem. New set of tires and the clunking, extra AWD engagement, and transmission temps went away.
    - ComputerGuru 6y ago
      Interesting story. And yes, I was specifically referring to full-time AWD with or without a rear bias, like that in the Audi Quattro (who I personally think does an excellent job). I actually don’t consider a car that doesn’t have full-time AWD to be AWD at all, isn’t that considered 4WD?
      - o-__-o 6y ago
        I understand AWD to be exactly that, all wheels providing driving traction. We have advanced long from the Audi 200 days to where part-time AWD is as simple as $700 in parts (for my car). 4WD (4x4) is full time (typically selectable but cannot be changed while in motion). 4WD has a greater gear ratio to really put power to the wheels that have grip, so while all 4WD cars can be considered AWD, AWD cannot be considered 4WD. I’m sure some jeep owner can give a better rundown on why 4WD is named the way it is..
        macintux 6y ago
        > typically selectable but cannot be changed while in motion Not true for a long time now. Manually locking hubs required egress while stopped but at some point 4wd tech progressed.
        frankchn 6y ago
        Yeah, the most advanced systems can switch between 4WD and RWD while the drivetrain is under considerable stress too. For instance, the F90 M5 can engage the front wheels on command while in the middle of a power slide and let the front wheels pull the car out of the slide.
        o-__-o 6y ago
        M5 is not 4WD. Just an electronically controlled clutch like my car.
        ComputerGuru 6y ago
  - aidenn0 6y ago
    I don't know if it does or does not actually cause issues, but the manual for my friends Subaru definitely says the tire wear needs to be even (possibly in pairs?). It came up when she got a nail through one tire about halfway through the lifetime.
    - o-__-o 6y ago
      Ugh this is my story right now. $500 cost for a new tire. I will probably get it patched and then put on a set of winter wheels while I figure out the next step
  - bayindirh 6y ago
    Opel Calibra is extremely sensitive to asymmetric tyre wear. The speed difference damages the third, central differential. To prevent the problem, you need to rotate your tyres periodically. It’s one of the main reasons why that car is notorious in terms of maintenance. Too bad, I love that car though.
- falcolas 6y ago
  The op isn’t in an awd vehicle. He’s in a Tesla with only RWD.
- Spooky23 6y ago
  None. Arguing with Tesla people on the internet is like arguing with vegans... not a productive exercise for either party. I have a guy at work who has been without a car for 4 months due to Tesla fuckups, and he basically defends Elon’s honor on the internet as a hobby.
  - donkeyd 6y ago
    It's almost like arguing with any other fanboy on the internet. Maybe the brand doesn't really make a difference, maybe it's just the being of a fanboy.
    - throwaway0a5e 6y ago
      Some fanboys are more numerous than others. Personally I find discussing Toyota on the internet to be far less productive than Tesla.
  - bookofjoe 6y ago
    Make Apple Great Again
Denzel 6y ago
This is not a bug. I also drive a Model 3, spiritedly. Of course, I’ve rotated my tires many times, on schedule, but I replace them all at the same time. It’s standard practice. I’ve never experienced OPs behavior. The algorithm is such that there’s a limit to the amount of “slippage” it will accept before traction control engages. A difference in tire diameters, exacerbated by a hard curve, leads to more slippage than the algorithm is willing to accept. What do you think would happen if traction control was off? :) Furthermore, there are unknowns here - OP hasn’t specified the diameter (between 2 and 8/32’s) of their old tires. They simply stated that the tires had enough tread to meet their personal standards. Clearly traction control sees the situation differently.
- jacquesm 6y ago
  Definitely a bug. If tires are within spec the traction control should not trigger, it should trigger when a wheel slips, not when it is in fact having good traction.
  - AndrewBissell 6y ago
    A bug? In a Tesla? Naaaaaaah ...
    - speedgoose 6y ago
      It's fine, they will update your car remotely and remove the bug. Eventually. By the end of a year. Still want one though.
      - wkearney99 6y ago
        tried driving a Taycan yet?
        speedgoose 6y ago
        No, there is no Porsche Taycan to rent in my area. It seems to be a very nice car.
bookofjoe 6y ago
Whoa, wait! >... for example, after a tire explosion for me... I'm 72 and have yet to experience a tire explosion or be in the vicinity of one. How many have you had?
- iforgotpassword 6y ago
  I've witnessed one on a huge truck about 300m in front of me. It was loud as hell, could feel it in my whole body. I was super confused and didn't realize what happened right away. Luckily there wasn't much traffic and the driver managed to pull over safely.
  - nikau 6y ago
    Trucks use retread tires to save money with the trade off of higher blowout rates. The driver could pull over safely as each axle has more than one tire. This is also why retreads are not popular these days (or illegal) for car use as you don't have redundancy if a tire blows.

by yholio 6y ago

aidenn0 6y ago

Many AWD cars require replacing tires in sets in the manual

ComputerGuru 6y ago
As a long-time owner of AWD performance vehicles (Midwest for you, possible snow eight months of the year!) I can assure that whether or not you replace your tires four, two, or even just one at a time, there are absolutely zero visible/immediately tangible repercussions and the issue described with the Tesla is absolutely not normal even under those circumstances. As for the long term ramifications, you’ll definitely see increased wear/camber on the opposing tire(a) and I’ve read it could theoretically cause issues with the diff, but I find that extremely hard to believe at least for the cats I’ve driven, because the front:back power ratio is dynamically recalculated and changed continuously depending on driving conditions. If it were 4WD rather than AWD, that might be the case though.
- o-__-o 6y ago
  Okay here is anecdotal experience. I had a set of treads on my rear tire at 15/32 while the fronts where at 9/32. Viscous coupled AWD with traction control via four-wheel braking. I first noticed something was up when the car would launch rather quickly. I added an odb-2 reader and saw my AWD clutch was engaging a lot. Thought this was by design due to my heavy foot. Then the clunking started. The AWD would rather stay engaged which puts strain on the transmission to shift harder. Over time this showed up as increased transmission temperatures. My transmission is sensitive to heat but has a poor design which makes any heat a very big deal. At about the same time I was researching new wheels and determined I could fit 9” wide tires in the rear vs 8.5” in the front. A staggered wheel set would give me more rear wheel power bias, but the closest I could get in tire size was still almost .5% larger in diameter. In all my research it turns out you need tires of the same size within 3/16 wear of each other to avoid non-full time AWD transmissions from doing dumb things like my car does. You see, the AWD clutch simply engages a power transfer unit and then depends on ABS to control power sent by the differential to individual wheels. That system needs to recalibrate itself regularly and it does this when the clutch disengages. When it doesn’t, all sorts of warnings are tripped (in my car I went down 6 floors of a spiraling parking garage exit at 15-20mph and at the 2nd floor a “service stabili-trak” icon appeared on my dashboard) In cars with a well designed AWD system this will not happen.. but most cars are not designed to engage in AWD for prolonged periods of time and are really there as a beefed up version of traction control. For instance my Torsen Quattro AWD Audi had full time AWD and never had this problem nor would a Nissan GT-R. But for that fancy Lexus or Hyundai AWD, you may want to make sure you stick to the recommended tire rotation schedule To end my story, I was at the service center and they mentioned I should get my transmission checked out by the bigger repair bay because of the clunking. I suggested it may be the wear of the tires and they agreed to see if that solved the problem. New set of tires and the clunking, extra AWD engagement, and transmission temps went away.
  - ComputerGuru 6y ago
    Interesting story. And yes, I was specifically referring to full-time AWD with or without a rear bias, like that in the Audi Quattro (who I personally think does an excellent job). I actually don’t consider a car that doesn’t have full-time AWD to be AWD at all, isn’t that considered 4WD?
    - o-__-o 6y ago
      I understand AWD to be exactly that, all wheels providing driving traction. We have advanced long from the Audi 200 days to where part-time AWD is as simple as $700 in parts (for my car). 4WD (4x4) is full time (typically selectable but cannot be changed while in motion). 4WD has a greater gear ratio to really put power to the wheels that have grip, so while all 4WD cars can be considered AWD, AWD cannot be considered 4WD. I’m sure some jeep owner can give a better rundown on why 4WD is named the way it is..
      - macintux 6y ago
        > typically selectable but cannot be changed while in motion Not true for a long time now. Manually locking hubs required egress while stopped but at some point 4wd tech progressed.
        frankchn 6y ago
        Yeah, the most advanced systems can switch between 4WD and RWD while the drivetrain is under considerable stress too. For instance, the F90 M5 can engage the front wheels on command while in the middle of a power slide and let the front wheels pull the car out of the slide.
        o-__-o 6y ago
        M5 is not 4WD. Just an electronically controlled clutch like my car.
      - ComputerGuru 6y ago
- aidenn0 6y ago
  I don't know if it does or does not actually cause issues, but the manual for my friends Subaru definitely says the tire wear needs to be even (possibly in pairs?). It came up when she got a nail through one tire about halfway through the lifetime.
  - o-__-o 6y ago
    Ugh this is my story right now. $500 cost for a new tire. I will probably get it patched and then put on a set of winter wheels while I figure out the next step
- bayindirh 6y ago
  Opel Calibra is extremely sensitive to asymmetric tyre wear. The speed difference damages the third, central differential. To prevent the problem, you need to rotate your tyres periodically. It’s one of the main reasons why that car is notorious in terms of maintenance. Too bad, I love that car though.
falcolas 6y ago
The op isn’t in an awd vehicle. He’s in a Tesla with only RWD.
Spooky23 6y ago
None. Arguing with Tesla people on the internet is like arguing with vegans... not a productive exercise for either party. I have a guy at work who has been without a car for 4 months due to Tesla fuckups, and he basically defends Elon’s honor on the internet as a hobby.
- donkeyd 6y ago
  It's almost like arguing with any other fanboy on the internet. Maybe the brand doesn't really make a difference, maybe it's just the being of a fanboy.
  - throwaway0a5e 6y ago
    Some fanboys are more numerous than others. Personally I find discussing Toyota on the internet to be far less productive than Tesla.
- bookofjoe 6y ago
  Make Apple Great Again

Denzel 6y ago

This is not a bug. I also drive a Model 3, spiritedly. Of course, I’ve rotated my tires many times, on schedule, but I replace them all at the same time. It’s standard practice. I’ve never experienced OPs behavior. The algorithm is such that there’s a limit to the amount of “slippage” it will accept before traction control engages. A difference in tire diameters, exacerbated by a hard curve, leads to more slippage than the algorithm is willing to accept. What do you think would happen if traction control was off? :) Furthermore, there are unknowns here - OP hasn’t specified the diameter (between 2 and 8/32’s) of their old tires. They simply stated that the tires had enough tread to meet their personal standards. Clearly traction control sees the situation differently.

jacquesm 6y ago
Definitely a bug. If tires are within spec the traction control should not trigger, it should trigger when a wheel slips, not when it is in fact having good traction.
- AndrewBissell 6y ago
  A bug? In a Tesla? Naaaaaaah ...
  - speedgoose 6y ago
    It's fine, they will update your car remotely and remove the bug. Eventually. By the end of a year. Still want one though.
    - wkearney99 6y ago
      tried driving a Taycan yet?
      - speedgoose 6y ago
        No, there is no Porsche Taycan to rent in my area. It seems to be a very nice car.

bookofjoe 6y ago

Whoa, wait! >... for example, after a tire explosion for me... I'm 72 and have yet to experience a tire explosion or be in the vicinity of one. How many have you had?

iforgotpassword 6y ago
I've witnessed one on a huge truck about 300m in front of me. It was loud as hell, could feel it in my whole body. I was super confused and didn't realize what happened right away. Luckily there wasn't much traffic and the driver managed to pull over safely.
- nikau 6y ago
  Trucks use retread tires to save money with the trade off of higher blowout rates. The driver could pull over safely as each axle has more than one tire. This is also why retreads are not popular these days (or illegal) for car use as you don't have redundancy if a tire blows.