Run Flat Tires

[rdlink]

I read another thread in this forum about someone having a flat tire in a Model S out of warranty, and Tesla's hourly price was going to cost him in the neighborhood of $300 to have a spare brought out. It led me to go through the forums and read some of the hodgepodge solutions people are using to have flat tire contingencies. Things like donut spares from other manufacturers, combinations of fix a flat/jacks/compressors, plug kits, etc..

That led me to think about run flats, and it makes me wonder if there is a technical reason why Tesla doesn't include run flats on their cars, or at least offer them as an option. Does anyone have any insight as to whether it's a technical issue, a cost issue, or what?

And before we get started: While I completely understand that there a multitude of opinions and viewpoints on run flats around ride quality, cost vs benefit, etc., a discussion of that is completely not the intention of this thread. Please, let's not derail the discussion on the personal feelings/pros and cons of run flats. Having driven two BMWs with run flat tires I understand their benefits and downsides.

I'd simply like to get into any intel someone might have about Tesla's decision, and/or to discuss technical issues that might preclude the use of run flats on the Model 3. Thanks.

 

[cantdecide]

In addition to the tradeoffs that all manufacturers need to consider, Tesla also...

* Fuel efficiency is really important as range is critically important. Tesla is a manufacturer where a 2% range gain is far more important than for any ICE in consumers minds. This matters for rolling resistance, tire weight, and suspension weight.
* Grip is also more important as drivers often treat their cars as sports cars, including with fast acceleration. The car is also judged on 0-60 times more than a Honda Odyssey is.

If Tesla offered nokian all weather run flats as an option (didn't affect Official rates range) I expect they would get quite a few takers.

 

[Ejl80]

I read another thread in this forum about someone having a flat tire in a Model S out of warranty, and Tesla's hourly price was going to cost him in the neighborhood of $300 to have a spare brought out. It led me to go through the forums and read some of the hodgepodge solutions people are using to have flat tire contingencies. Things like donut spares from other manufacturers, combinations of fix a flat/jacks/compressors, plug kits, etc..

I haven't bought a car that came with a spare tire for a long time. I also, like you came from the BMW world and would always switch from run flats. There is no technical reason that Tesla would not be able to use run flats, aside from economy, ride quality, etc. A typical tow company starts at 85-100 just to come out, even for a lockout or similar issue, so 300 to bring an actual spare seems like a reasonable price.

 

[rdlink]

I haven't bought a car that came with a spare tire for a long time. I also, like you came from the BMW world and would always switch from run flats. There is no technical reason that Tesla would not be able to use run flats, aside from economy, ride quality, etc. A typical tow company starts at 85-100 just to come out, even for a lockout or similar issue, so 300 to bring an actual spare seems like a reasonable price.

$300 is not a horrible price. But if the difference in cost of run flats is $200 or so for the set, and the range isn't negatively affected by run flats I would prefer to have the peace of mind. Because even at $300 you're kinda hosed if you're out of cell phone range when you have a flat.

I bought my first BMW that came with run flats used. The ride was harsh, and I was pretty eager to get rid of them once they wore out, and replace them with non run flats. Then I backed over a piece of angle iron in my garage one day and sliced the right rear tire open. I just pulled out of the garage and drove to the tire store about 6 miles from my house. My attitude began to change.

Later I found out that the poor ride I was attributing to the run flats was actually a product of a bad strut. Even though I had asked three different shops to give me their opinion, and all three of them tried to blame it on the run flats. My current BMW (a 2017) has run flats, and it's the best riding car I have ever owned.

 

[bradhs]

Our BMW 750 has run-flats. While they are great in the safety department, they offer me peace of mind that my wife and children won't get stranded anywhere. For me, the loss of ride quality don't make them worth it. I carry a few things in my car to help me recover from a flat quickly.

https://www.amazon.com/Victor-22-5-...36506832&sr=8-6&keywords=temporary+tire+plugs

https://www.amazon.com/Victor-22-5-...pID=41fZpcIcP6L&preST=_SX300_QL70_&dpSrc=srch

...Also a handful of plastic gloves and portable air compressor.

With that you're pretty mush set, unless you're in a suit, then you're screwed.

 

[Runebane]

My old car had run flat tires from the factory, but since I use the freeway for 90% of my driving, run flats were a bad choice. Unless you catch it right away, all they end up doing is disintegrating on the freeway and cause more problems. After nearly wrecking when the front left tire went out, I had them replaced with normal tires. At least then I could see when they went flat.

If all you do is city driving then yes, run flats would be a good choice. But if you do freeway/highway driving, not so much.

 

[bradhs]

This is no longer an issue since newer cars warn when tire pressure is low.

My old car had run flat tires from the factory, but since I use the freeway for 90% of my driving, run flats were a bad choice. Unless you catch it right away, all they end up doing is disintegrating on the freeway and cause more problems. After nearly wrecking when the front left tire went out, I had them replaced with normal tires. At least then I could see when they went flat.

If all you do is city driving then yes, run flats would be a good choice. But if you do freeway/highway driving, not so much.

 

[Ejl80]

$300 is not a horrible price. But if the difference in cost of run flats is $200 or so for the set, and the range isn't negatively affected by run flats I would prefer to have the peace of mind. Because even at $300 you're kinda hosed if you're out of cell phone range when you have a flat.

I bought my first BMW that came with run flats used. The ride was harsh, and I was pretty eager to get rid of them once they wore out, and replace them with non run flats. Then I backed over a piece of angle iron in my garage one day and sliced the right rear tire open. I just pulled out of the garage and drove to the tire store about 6 miles from my house. My attitude began to change.

Later I found out that the poor ride I was attributing to the run flats was actually a product of a bad strut. Even though I had asked three different shops to give me their opinion, and all three of them tried to blame it on the run flats. My current BMW (a 2017) has run flats, and it's the best riding car I have ever owned.

Ahh. I'm so used to the east coast, there basically isn't such a thing as out of cell phone range. Newer run flats are much better, so the shops still may have been right. The tires I like running aren't available in run flats, so it would make it a non starter anyway.

 

[rdlink]

Ahh. I'm so used to the east coast, there basically isn't such a thing as out of cell phone range. Newer run flats are much better, so the shops still may have been right. The tires I like running aren't available in run flats, so it would make it a non starter anyway.

It was the same tires. Just replacing the struts stopped the crashing over bad bumps, and made the tires seem 10X better.

 

[Runebane]

This is no longer an issue since newer cars warn when tire pressure is low.

That car also did, not that it helped. Tire pressure warnings only go off after a certain amount of pressure is lost. If the flat happens on the freeway, you most likely are not going to A) get the notice at all or B) not see the little amber light tick on as you keep driving.

 

[chillaban]

That car also did, not that it helped. Tire pressure warnings only go off after a certain amount of pressure is lost. If the flat happens on the freeway, you most likely are not going to A) get the notice at all or B) not see the little amber light tick on as you keep driving.

New TPMS systems warn rather quickly when there's a sudden loss of pressure. That's far more sensitive compared to the slow/gradual deflation warning.

And both on the Model 3 and even modern BMWs, there is a clear text warning that one of your tires is flat, rather than just the TPMS icon (that was a terrible idea, what were they thinking...)

 

[Runebane]

New TPMS systems warn rather quickly when there's a sudden loss of pressure. That's far more sensitive compared to the slow/gradual deflation warning.

And both on the Model 3 and even modern BMWs, there is a clear text warning that one of your tires is flat, rather than just the TPMS icon (that was a terrible idea, what were they thinking...)

Yeah my other car was a 2012 model and all it did was the yellow TPMS icon. Unfortunately with low profile run flats, you can't visually see if it's flat. And it's good to know you get a different message for a real flat not just low tire pressure.

 

[rluciano]

Our BMW 750 has run-flats. While they are great in the safety department, they offer me peace of mind that my wife and children won't get stranded anywhere. For me, the loss of ride quality don't make them worth it. I carry a few things in my car to help me recover from a flat quickly.

https://www.amazon.com/Victor-22-5-...36506832&sr=8-6&keywords=temporary+tire+plugs

https://www.amazon.com/Victor-22-5-...pID=41fZpcIcP6L&preST=_SX300_QL70_&dpSrc=srch

...Also a handful of plastic gloves and portable air compressor.

With that you're pretty mush set, unless you're in a suit, then you're screwed.

Just out of curiosity, why both types of tire repair plugs?

 

[Adam3]

Our BMW 750 has run-flats. While they are great in the safety department, they offer me peace of mind that my wife and children won't get stranded anywhere. For me, the loss of ride quality don't make them worth it. I carry a few things in my car to help me recover from a flat quickly.

https://www.amazon.com/Victor-22-5-...36506832&sr=8-6&keywords=temporary+tire+plugs

https://www.amazon.com/Victor-22-5-...pID=41fZpcIcP6L&preST=_SX300_QL70_&dpSrc=srch

...Also a handful of plastic gloves and portable air compressor.

With that you're pretty mush set, unless you're in a suit, then you're screwed.

Do you carry needle nose pliers as well? To pull out the nail/screw/etc.

 

[voip-ninja]

That car also did, not that it helped. Tire pressure warnings only go off after a certain amount of pressure is lost. If the flat happens on the freeway, you most likely are not going to A) get the notice at all or B) not see the little amber light tick on as you keep driving.

You can drive on a run flat at 50 mph for about 50 miles. They do not “rapidly disintegrate”. The warning on my BMW was a large lamp, notification on the infotainment screen and a chime and was impossible to not notice.

The main advantage of run flats is letting you get safely to a service station without having to exit your vehicle and risk getting run over, getting stuck with a flat in a bad neighborhood or miles from help, etc.

I wouldn’t recommend them on the M3. They are very stiff and the car suspension needs to be designed around them or the ride will suffer.

Additionally they are heavy and will probably affect the efficiency.

 

[EnrgyNDpndnce]

You can drive on a run flat at 50 mph for about 50 miles. They do not “rapidly disintegrate”. The warning on my BMW was a large lamp, notification on the infotainment screen and a chime and was impossible to not notice.

The main advantage of run flats is letting you get safely to a service station without having to exit your vehicle and risk getting run over, getting stuck with a flat in a bad neighborhood or miles from help, etc.

I wouldn’t recommend them on the M3. They are very stiff and the car suspension needs to be designed around them or the ride will suffer.

Additionally they are heavy and will probably affect the efficiency.

Hey VOIP, you changed your avatar! Guess you got tired of constantly getting kicked in the jibletts huh? I liked the other one, but this one is actually better. Hope you get your car soon! (And I hope I do too!)

 

[Runt8]

And before we get started: While I completely understand that there a multitude of opinions and viewpoints on run flats around ride quality, cost vs benefit, etc., a discussion of that is completely not the intention of this thread. Please, let's not derail the discussion on the personal feelings/pros and cons of run flats. Having driven two BMWs with run flat tires I understand their benefits and downsides.

What if ride quality or cost vs. benefit were the main reasons Tesla didn’t include them?

 

[Adam3]

You can drive on a run flat at 50 mph for about 50 miles. They do not “rapidly disintegrate”. The warning on my BMW was a large lamp, notification on the infotainment screen and a chime and was impossible to not notice.

The main advantage of run flats is letting you get safely to a service station without having to exit your vehicle and risk getting run over, getting stuck with a flat in a bad neighborhood or miles from help, etc.

I wouldn’t recommend them on the M3. They are very stiff and the car suspension needs to be designed around them or the ride will suffer.

Additionally they are heavy and will probably affect the efficiency.

Agreed. It depends on tire size but I've always heard run flats are 2-5lbs heavier than their non-RFT counterpart. They also have much stiffer sidewalls which leads to a harsher ride.

 

[rdlink]

What if ride quality or cost vs. benefit were the main reasons Tesla didn’t include them?

Then it's not a technical reason, like absurdly low range, insanely excessive wear or some weird and non obvious safety reason would be.

Both ride quality and cost vs benefit are reasons that users can weigh for themselves, and decide whether it's worth it to them. For instance, I re-configured my Model 3 with Aeros because I decided I didn't want the loss in range and potential harsher ride that would come from 19" sport wheels.

 

[Ejl80]

Then it's not a technical reason, like absurdly low range, insanely excessive wear or some weird and non obvious safety reason would be.

Both ride quality and cost vs benefit are reasons that users can weigh for themselves, and decide whether it's worth it to them. For instance, I re-configured my Model 3 with Aeros because I decided I didn't want the loss in range and potential harsher ride that would come from 19" sport wheels.

It absolutely is a technical reason. The same reason certain suspension components are chosen over other ones, etc. To meet their engineering goals for the customer experience.