My Honda CR-V TPMS uses the wheel speed sensors, instead of TPMS sensors in each wheel. And the hybrids don't come with a spare tire (get an inflator with a can of Slime instead). Can I consider getting run-flat tires? Would they interfere with the way indirect TPMS works?
Indirect TPMS and Run Flats
- Thread starter sjw91
- Start date
Run flats weigh nearly twice as much as normal tires, can be difficult to install and cost a good bit more. If you're worried about being stranded with an unrepairable flat, I would just buy a $20 donut spare from a junkyard that fits, and toss it in the back.
You're thinking of 1st generation run flats. They have come a long way. On my 99 Corvette they sucked, but the ones on my 2019 ride and perform very well. They only weigh a couple pounds more than non-RFTs. No problem installing on the rims. Cost is maybe $200 more per set.
I bought some used ones 10 years ago for a Cadillac and couldn't believe how heavy they were and how difficult those stiff sidewalls were to mount on the rim.
I don't see how this would impact indirect TPMS....you inflate them to whatever psi you want, set the TPMS in the car, and drive. If will go off if the ABS wheel speed sensors indicate that a tire(s) are spinning at a different speed than the others indicating the size has changed indicating that you are low...regualar tire or run flat...no difference.
Thanks. Since the run flats maintain their shape without pressure, I wondered if the indirect system would pick it up.
I would think so because it won't be the exact size would be my take.
You can use run flats with indirect TPMS. There will be no problems 
The only runflats worth buying are the Bridgestone DriveGuard.
It shouldn't be a problem. Remember, direct or indirect, the light only comes on when it's 25% below the factory spec pressure, so the indirect will notice the bad tire spinning 25% faster than the other three.
They maintain their shape better than regular tires, but still not 100%. There will still be some difference that the indirect sensors can detect that the naked eye can't detect.
The only runflats worth buying are the Bridgestone DriveGuard.
It shouldn't be a problem. Remember, direct or indirect, the light only comes on when it's 25% below the factory spec pressure, so the indirect will notice the bad tire spinning 25% faster than the other three.
They maintain their shape better than regular tires, but still not 100%. There will still be some difference that the indirect sensors can detect that the naked eye can't detect.
I hear the DriveGuard Plus are a notable improvement over the previous gen?You can use run flats with indirect TPMS. There will be no problems
The only runflats worth buying are the Bridgestone DriveGuard.
The DriveGuards are indeed nice tires. Very sticky, great go-kart handling. Unfortunately they are a pain on our rough roads. Too harsh, a jarring ride. If you have smooth roads they are great. The newer Plus version should be improved but at a higher cost. RF tires make sense on my Mini that doesnt have room for a spare but I gave up on the RFs. If you get a puncture you have to replace the tire anyway, at least if you keeping driving up to the allowable 50 miles.
Yes, if you are willing to throw the tire away. Very, VERY expensive proposition is AWD and then you have to change all 4.
RFT IMO goes only on TPMS! You will catch drop in pressure and can save tire. If you keep driving on it, it becomes expensive.
In BMW world where RFT are 20+ years present, Bridgestone RFT is considered by far worst option compared to Michelin, Continental and Pirelli.You can use run flats with indirect TPMS. There will be no problems
The only runflats worth buying are the Bridgestone DriveGuard.
It shouldn't be a problem. Remember, direct or indirect, the light only comes on when it's 25% below the factory spec pressure, so the indirect will notice the bad tire spinning 25% faster than the other three.
They maintain their shape better than regular tires, but still not 100%. There will still be some difference that the indirect sensors can detect that the naked eye can't detect.
that would mean tpms would never react on low profile tyres. To increase the rpm by 25% means reducing radius, diameter or circumference by 25%, not going to happen
I have no knowledge of run-flats here - just that an indirect TPMS should show the tire lost some air. How exactly do they work?
The air still keeps tire inflated. The construction allows you to drive up to 50mls without air. But at that point, tire is compromised. So yeah, you can run them, but if tire starts to collapse for speed sensor to puck it up, that tire is done!
whoops yeah you're right. The pressure going down 25% wouldn't reduce the radius by 25% but would still be able to trigger the tpms.
The runflat sidewall difference doesn't come into play until the tire is almost at zero psi or in the single digits. At something closer to correct pressure, definitely at 75% of correct pressure, it is more similar to regular tires in diameter, sidewall thickness, etc.
Does Bridgestone make some of the OE BMW RFT tires? Remember that OE tires are not the same as aftermarket
Their OE runflats aren't the same as the Driveguard, which is designed for cars that didn't originally come with them from the factory.
they probably are
Ah ok. So you don't think the indirect/ABS speed sensor system would "see" this?
Nope. RFT will keep its shape. Now, whether tire is damaged or not is up in the air. But, are you willing to risk it?
If that Cr-V has space for donut, just go donut.
Also, generally these Asian manufacturers slap RFT without adjusting suspension. Slap RFT on CR-V and that is going to be a rough ride.
HRS (BMW runflat approved) from Hankook won't totally keep shape. ask me how i know... if you have a sudden puncture and lose a great amount of air, it will appear deflated. not as deflated as a regular tire, but you can't definitely drive on it without wearing the sidewalls. i had that very experience today. and they are so noisy underinflated that you can't miss the problem. 225/45 R17
