Retro fitting runflats?
Discussion
I guess the issue is without a tpms when would you know if you had lost pressure?, the theory of them is if you have a flat you reduce your speed and continue only for a certain distance.
In reality if it went to very low pressure you would know as its obvious (having driven with a punctured runflat).
In reality if it went to very low pressure you would know as its obvious (having driven with a punctured runflat).
I am only asking for advise, as i will need to replace a set soon, and i already have a set of runflats in the same size with good tread. If its not possible, I'll shell out for conventional tyres. The car is up for sale when the winter is coming to an end, so I'm not up for spending a fortune on a set if i don't have to.
Edited by kiwifraser on Thursday 10th January 18:50
Ozzie Osmond said:
You NEED tyre pressure monitor with runflats. Otherwise you risk a catastrophic high speed blowout if you are driving on a puncture.
Whan I had a puncture the only way I knew was from the TPMS warning.
.
What a load of alarmist nonsense. They're rated to drive at about 50 mph for 50 miles with puncture and yet you think you're going to get a high speed blowout?!Whan I had a puncture the only way I knew was from the TPMS warning.
.
I'm not the best driver but it was hugely apparent when my MINI's tyres had lost a couple of PSI because of the marked effect on handling/ride due to their construction and being very sensitive to correct inflation. If you can't notice you have a puncture without a TPMS then I do worry.
Jonnas said:
......plus you'll regret it....
If performance mattered, i wouldn't be asking the question 
This is a potential solution to keep the shed on the road for a couple of months. Some sturdy sidewalls might actually be a good thing given the monstrous potholes in Glasgow at the moment
So, is the consensus:
1 - Insta-death 400 yards from home on the way to get shopping from Sainsburys
2 - Not legal, desirable, or in any circumstances suitable.
3 - Not an ideal solution without a TPMS, but the dog should still make it to the park for a walk ok if he travels in the boot of a car with such tyres.
4 - An easy solution, to a problem that is unlikely to have any real adverse effects on the local runs to the tip.
1 - Insta-death 400 yards from home on the way to get shopping from Sainsburys
2 - Not legal, desirable, or in any circumstances suitable.
3 - Not an ideal solution without a TPMS, but the dog should still make it to the park for a walk ok if he travels in the boot of a car with such tyres.
4 - An easy solution, to a problem that is unlikely to have any real adverse effects on the local runs to the tip.
That's not normal round these parts.
LongLiveTazio said:
No they don't, loads of cars use runflats without TPMS.
From Bridgestone:"The vehicles tyre pressure monitoring systems (TPMS) alerts a driver when a tyre's pressure drops below agreed limits. Since Since RFT technology keeps tyres functioning for 80km (50 miles) at 80 km/h (50 mph) after losing pressure, a driver might not otherwise notice the loss of pressure. Therefore, any vehicle using tyres with Run-Flat technology must be equipped with a tyre pressure monitoring system."
and as to fitting:
"Tyres with Run-Flat Technology should only be fitted to vehicles that are specifically designed for Run-Flats (Run-Flat Technology as standard equipment), or at least, cars designed with that option in mind (Run-Flat Technology as optional equipment). Any vehicle that uses Run-Flat Technology requires a Tyre Pressure Monitoring System or the driver might not realize that a tyre has been punctured. Furthermore, tyres with Run-Flat Technology are specifically tuned to the suspension of individual vehicles meaning they are inappropriate for fitment to other vehicles."
Edited by Monty Python on Thursday 10th January 21:26
Edited by Monty Python on Thursday 10th January 21:29
Yes, if you believe the marketing b
ks. I have had three cars with RFTS, you do not need TPMS and you can notice when it has lost even a few PSI. If you can't tell you have a puncture you need to hand in your driver's license. And if the car's suspension was tuned for them then people would not fit conventional tyres to improve ride and grip. However, they do for good reason, yet you wouldn't apply the same logic in reverse and say that someone with a 3-series who wanted to fit non-RFTs was risking death by deviating from OEM spec.
People seem to have lost all semblance of reality just because someone in a suit tells them that something is 'right' for their car, RFTs have been around for decades ffs.
ks. I have had three cars with RFTS, you do not need TPMS and you can notice when it has lost even a few PSI. If you can't tell you have a puncture you need to hand in your driver's license. And if the car's suspension was tuned for them then people would not fit conventional tyres to improve ride and grip. However, they do for good reason, yet you wouldn't apply the same logic in reverse and say that someone with a 3-series who wanted to fit non-RFTs was risking death by deviating from OEM spec. People seem to have lost all semblance of reality just because someone in a suit tells them that something is 'right' for their car, RFTs have been around for decades ffs.
LongLiveTazio said:
I'm not the best driver but it was hugely apparent when my MINI's tyres had lost a couple of PSI because of the marked effect on handling/ride due to their construction and being very sensitive to correct inflation. If you can't notice you have a puncture without a TPMS then I do worry.
You, Sir, are talking absolute drivel.1. I defy any driver to sense "a couple of PSI" difference in tyre pressure. That's well within the normal range of parked car to driving car variation.
2. All the manufacturers of runflats and all the manufacturers of cars with runflats and all the construction and use regulations say you need TPMS. But you know better.
They need it because the average motorist is a moron and cannot be bothered to check tyre pressure, in the same way that people don't bother checking their oil, washer fluid or myriad other things that are described in the manual in excruciating detail. Anything which is marketed as being able to run with a puncture is of course therefore going to be subject to an extra measure to avoid people sueing them if they don't notice, despite the fact the tech has been around since forever.
And yes, you can notice a couple of PSI drop, RFTs are far more sensitive than conventional and have to be kept at higher pressures. The way the compound/tread works is different and the drop-off in performance due to harder compound is much more noticeable. Anyone with a BMW with RFTs will tell you the same.
And yes, you can notice a couple of PSI drop, RFTs are far more sensitive than conventional and have to be kept at higher pressures. The way the compound/tread works is different and the drop-off in performance due to harder compound is much more noticeable. Anyone with a BMW with RFTs will tell you the same.
I used to have a 530d and the TPMS used to get a bit dodgy from time to time, it would flag a problem so I would stop and check the pressures, put a few psi in one occasionally. Once I did this and the tyre had a rip on the inner shoulder so would retain no air. Obviously I'm not Schumacher but you literally couldn't tell doing normal driving whether it had 35psi or 0psi. Maybe I need some of these special driving skills where you can notice a few psi drop?
kiwifraser said:
I am only asking for advise, as i will need to replace a set soon, and i already have a set of runflats in the same size with good tread. If its not possible, I'll shell out for conventional tyres. The car is up for sale when the winter is coming to an end, so I'm not up for spending a fortune on a set if i don't have to.
As your selling i'd bung them on to see you through, maybe check pressures more frequently.Edited by kiwifraser on Thursday 10th January 18:50
I have driven my car on a very flat runflat and it was obvious the tyre was flat, especially when i hit a bit of road that had been scraped for resurfacing, that wasnt fun even at 30mph!
cb31 said:
I used to have a 530d and the TPMS used to get a bit dodgy from time to time, it would flag a problem so I would stop and check the pressures, put a few psi in one occasionally. Once I did this and the tyre had a rip on the inner shoulder so would retain no air. Obviously I'm not Schumacher but you literally couldn't tell doing normal driving whether it had 35psi or 0psi. Maybe I need some of these special driving skills where you can notice a few psi drop?
I think I'll have to join you. I've had my 335d for thre years and in that time I've never noticed any change in handling with a loss of up to 10psi.Edited by Monty Python on Thursday 10th January 22:00
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