Runflat on non-Runflat car

Runflat on non-Runflat car

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Discussion

Tommie38

Original Poster:

884 posts

207 months

Friday 2nd May
quotequote all
As above, dad has just fitted a runflat Bridgestone to his 2020 X1. So the car has 3 non runflats and 1 runflat. All are the same tyre type (T005 I think) just different in terms of the runflat tech. For the avoidance of doubt, it comes on non runflats from the factory.

Thoughts?

Part of me is thinking that it doesn’t really matter in the grand scheme of things and to just leave it. That said, apart from the general irritant, one of the concerns I have is that the ride is already poor and fitting a RFT will make it even worse.

SAS Tom

3,648 posts

187 months

Friday 2nd May
quotequote all
It’s probably not great but I doubt it’s a disaster either.

Puddenchucker

4,808 posts

231 months

Friday 2nd May
quotequote all
Does the car have tyre pressure sensors?
If not, how would you know if the car had a puncture in the runflat?

SAS Tom

3,648 posts

187 months

Friday 2nd May
quotequote all
Puddenchucker said:
Does the car have tyre pressure sensors?
If not, how would you know if the car had a puncture in the runflat?
Because the pressure would drop like a normal tyre.

Sebring440

2,628 posts

109 months

Friday 2nd May
quotequote all
This is a serious question: why did your father fit the runflat?

They are completely different in the driving characteristics and having two totally different tyres on one axle could affect the handling behaviour. There may be insurance complications also. It's a "modification", after all (if the car came with non-runflats from the factory).


BunkMoreland

1,787 posts

20 months

Friday 2nd May
quotequote all
Tommie38 said:
As above, dad has just fitted a runflat Bridgestone to his 2020 X1. So the car has 3 non runflats and 1 runflat. All are the same tyre type (T005 I think) just different in terms of the runflat tech. For the avoidance of doubt, it comes on non runflats from the factory.

Thoughts?

Part of me is thinking that it doesn’t really matter in the grand scheme of things and to just leave it. That said, apart from the general irritant, one of the concerns I have is that the ride is already poor and fitting a RFT will make it even worse.
What he needs to do, is go back to the tyre place, politely point out their mistake and get a normal tyre fitted! And the refund in price difference!

Mr Tidy

26,216 posts

140 months

Friday 2nd May
quotequote all
SAS Tom said:
Puddenchucker said:
Does the car have tyre pressure sensors?
If not, how would you know if the car had a puncture in the runflat?
Because the pressure would drop like a normal tyre.
My Dad used to check his tyre pressures every week back in the 60s, but I doubt most people check them once a year these days!

So how would his dad know the pressure had dropped? Runflats don't look flat when they have no air in them, that's the whole point of them. But you are only supposed to drive below 50mph and for a limited mileage with a flat one as the inside breaks up after that.

If the car has a TPMS it might be OK, but if it operates from sensors in the valves that wheel would need to have a sensor fitted. Older BMWs monitored it via the wheel speed sensors.

I wouldn't want to drive a car on 3 normal tyres and 1 run-flat!


Pica-Pica

15,032 posts

97 months

Friday 2nd May
quotequote all
With run-flat tyres a TPMS is mandatory. Also the wheel must have a JJ section rim with run-flats.
I would not be happy with that his set-up.

Edited by Pica-Pica on Friday 2nd May 23:00

mph999

2,758 posts

233 months

Friday 2nd May
quotequote all
As mentioned, you have to have TPMS and the correct wheel type for runlets, so that's an immediate MOT fail.

The handling is going to be awful as well.

If involved in a big enough accident the the Police investigated and looked over the car, that setup may raise some awkward questions ....

SAS Tom

3,648 posts

187 months

Saturday 3rd May
quotequote all
Mr Tidy said:
SAS Tom said:
Puddenchucker said:
Does the car have tyre pressure sensors?
If not, how would you know if the car had a puncture in the runflat?
Because the pressure would drop like a normal tyre.
My Dad used to check his tyre pressures every week back in the 60s, but I doubt most people check them once a year these days!

So how would his dad know the pressure had dropped? Runflats don't look flat when they have no air in them, that's the whole point of them. But you are only supposed to drive below 50mph and for a limited mileage with a flat one as the inside breaks up after that.

If the car has a TPMS it might be OK, but if it operates from sensors in the valves that wheel would need to have a sensor fitted. Older BMWs monitored it via the wheel speed sensors.

I wouldn't want to drive a car on 3 normal tyres and 1 run-flat!
If it’s on a non run flat rim, it’ll look flat if it has no air in it.

Pit Pony

9,866 posts

134 months

Saturday 3rd May
quotequote all
SAS Tom said:
If it’s on a non run flat rim, it’ll look flat if it has no air in it.
No it won't.

In my experience with a none runflat, if you pick up a slow puncture on a long run, eventually you feel the car is less stable and if sensible, stop to inspect.

On a run flat, the deterioration in handling will be less, you probably won't notice and you could exceed the 50 mph 50 mile limit (or whatever it has) thus making the tyre unsafe.



BOR

4,961 posts

268 months

Saturday 3rd May
quotequote all
A 2020 X1 will have TPMS, and will have had both tyre types on the same wheel as an option.

I would be more concerned about a mismatch in tyre diameter.

Other than that, I doubt you can tell the difference driving.

All completely OK in my opinion.

Blue62

9,700 posts

165 months

Saturday 3rd May
quotequote all
Sebring440 said:
This is a serious question: why did your father fit the runflat?

They are completely different in the driving characteristics and having two totally different tyres on one axle could affect the handling behaviour. There may be insurance complications also. It's a "modification", after all (if the car came with non-runflats from the factory).
^^ What he said. I can’t believe the car is drivable with such a mix. Some years ago I replaced the rears only on a BMW with runflats, I returned to the tyre depo within a few miles, I was shocked at the handling.

Tommie38

Original Poster:

884 posts

207 months

Saturday 3rd May
quotequote all
Puddenchucker said:
Does the car have tyre pressure sensors?
If not, how would you know if the car had a puncture in the runflat?
Yes it does

Tommie38

Original Poster:

884 posts

207 months

Saturday 3rd May
quotequote all
Sebring440 said:
This is a serious question: why did your father fit the runflat?

They are completely different in the driving characteristics and having two totally different tyres on one axle could affect the handling behaviour. There may be insurance complications also. It's a "modification", after all (if the car came with non-runflats from the factory).
He made a mistake when ordering.

Tommie38

Original Poster:

884 posts

207 months

Saturday 3rd May
quotequote all
BunkMoreland said:
Tommie38 said:
As above, dad has just fitted a runflat Bridgestone to his 2020 X1. So the car has 3 non runflats and 1 runflat. All are the same tyre type (T005 I think) just different in terms of the runflat tech. For the avoidance of doubt, it comes on non runflats from the factory.

Thoughts?

Part of me is thinking that it doesn’t really matter in the grand scheme of things and to just leave it. That said, apart from the general irritant, one of the concerns I have is that the ride is already poor and fitting a RFT will make it even worse.
What he needs to do, is go back to the tyre place, politely point out their mistake and get a normal tyre fitted! And the refund in price difference!
Not really an option. Blackcircles, ordered online and fitted by a garage. I think he would agree it is his mistake.

Sebring440

2,628 posts

109 months

Saturday 3rd May
quotequote all
Tommie38 said:
Not really an option. Blackcircles, ordered online and fitted by a garage. I think he would agree it is his mistake.
In that case, I really surprised the garage thought it was OK to fit the tyre. Very unprofessional of them.


Tommie38

Original Poster:

884 posts

207 months

Saturday 3rd May
quotequote all
BOR said:
….
Other than that, I doubt you can tell the difference driving.

All completely OK in my opinion.
I suspect this is it, just whether or not my OCD or indeed his can tolerate it. Both he and I are ‘ matched premium tyres’ type people, just this time he got the matching part wrong! Long story but the tyre on the other side is the same age just non RFT. So diameter etc not an issue.

Tommie38

Original Poster:

884 posts

207 months

Saturday 3rd May
quotequote all
Sebring440 said:
Tommie38 said:
Not really an option. Blackcircles, ordered online and fitted by a garage. I think he would agree it is his mistake.
In that case, I really surprised the garage thought it was OK to fit the tyre. Very unprofessional of them.
I guess if you think the business model through, they have taken a booking that Blackcircles probably pays them £15 for. They see the car for the first time when it arrives for fitting. If they turn the car away they do not get paid. I doubt anybody checks anything.

We’ve both been buying tyres for years, first time it has happened.

BunkMoreland

1,787 posts

20 months

Saturday 3rd May
quotequote all
Tommie38 said:
Not really an option. Blackcircles, ordered online and fitted by a garage. I think he would agree it is his mistake.
Then go back to the tyre fitter point out the problem and ask how they can help him. They might/might not be happy to take the tyre back (so they can sell it as a part worn if he's only just had it fitted) and give him a discount on a new correct tyre. A sensible conversation is worth having. They are within their rights to say No obviously.

Even if he has to pay for a new tyre totally, it needs rectifying.


As for comments about tpms and mot. Its only a mot fail if its "obviously malfunctioning"
manual said:
Tyre pressure monitoring system malfunctioning or obviously not working - Major
https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles/5-axles-wheels-tyres-and-suspension