Run flat distance when flat

[Mr Run Flat]

Run Flat (and Broke) - A cautionary tale.

Having recently had a run flat tyre pressure loss in BMW 530d with family in car on the motorway and been unable to find anything on what to do I thought I'd post my experience:

We were 120 miles from holiday destination on a bank holiday weekend about 11pm, travelling at 70mph on M5 - orange warning light comes on "low pressure, stop carefully" so I take next exit to services. Couldn't really tell it was flat apart from handling was a bit swimmy on curves but OK on straights. Tried to fill tyre but got no reading. Found tyre filler in boot but wasn't sure if it would make things worse so didn't use it. Hotel at services was full so avoided motorway in case of tyre failure and continued on at 40 mph on A roads to next town, at 1am and all hotels closed/full. Continue on checking at hotels along the 120 mile journey but all full. Tyre tapping sound was now audible as we arrived at destination at 4am.

Had to wait until Tuesday to get replacements delivered as non stock tyres. Discovered front passenger also needed replacing. The Tyre shop said loss of pressure was caused by the car's tracking being out and they showed me how it had eroded the inner wall. They said it could of been avoided if tracking was OK. But the tracking is knocked out driving over pot holes & speed bumps.

Then, next day after 30 minutes travelling back from holiday, tyre pressure light comes on again. We pull over and found a garage (Fiat dealership Dorchester) they kindly identified the problem as a cracked alloy - apparently replacements are only direct from BMW. Found a BMW dealership, left the car got a hire hire and drove home.

For safety I did all 4 in the end.

I think I may of cracked the alloy driving 120 miles on the run flat, if it happens again I would use the tyre filler.

Glad I had the run flats though, especially after losing pressure on Motorway with my little uns in the back, It would of been scary if it was a regular tyre.

I hope this helps some unfortunate person who gets in a similar situation. Cheers!

[is200]

I managed to get a puncture on one of my run flats a week after buying the car, 430d gran coupe, fifty miles from home on a Sunday night with family in car. Came off the motorway, tried putting air in the tyre and nothing.

A really nice guy in a 5 series came over to me and gave me his can of tyre sealant, unfortunately that didn’t work due to the size of the hole in the tyre (which we found when the tyre sealant squirted out!).

Ended up driving home at 40/50mph using backroads with the smell of heated rubber getting stronger, was half expecting to have to get a new alloy as 19”. Had to cancel work trip for the Monday as needed to drive to client site which was over 200 miles away.

Got a new tyre on the Monday afternoon and also ordered a space saver from BMW, takes up space in the boot but worth it for my peace of mind. Luckily alloy was ok.

[shakindog]

As far as I’m aware it’s 50mph for 50-100 miles not sure which but it will tell you in the handbook exactly.
As long as you didn’t hit any potholes at speed you should be ok and not damaged the wheel. As without air in the tyre the impact forces are directed in the wheel more.
Should be fine tho

[smashy]

Have to say I have probably done 150 miles going over 50mph many times on that journey with no issues

[Mr Tidy]

The Owner's Handbook for my E91 325i says with a low load (1 or 2 people and no luggage) 150 miles.

With a moderate load (2 people and full load area, or 4 people and empty load area) 90 miles.

With a full load (4 people or more and load area full) or towing a trailer 30 miles.

And in all cases at no more than 50 mph.

Luckily the only 2 times it happened to me was when I had a 123d and it was less than 20 miles from home!

From memory my E86 has similar load/distance parameters, but I think if you can keep decent pressure in them by topping up with a compressor you may manage more. You certainly stand a better chance of the tyre being repairable if it hasn't ben run totally flat!

[Denis O]

E85 went 12 miles and the tyre was shot. When they pulled it off it was full of little black rubber balls, delamination of sidewalls.

I changed all 4 to non RF and got a transformed car.

RFT. Hateful things.

[ThunderSpook]

Yep, can’t have a thread about how useful runflats are without someone popping up to say how much better his car is now he’s got rid of them!

For me the ability to get my family off a busy motorway with a flat tyre will always outweigh anything.

[Pica-Pica]

I have run flats in a stepped set up. My left front alloy is badly Kerbed (my fault entirely). When tyres get worn down, I plan to get a new alloy, re-furnish the old one and keep that as a spare at home. The other alternative (for me) is drop to a square set up of cross climates, and keep a 5th at home as spare, and a can of goo in the boot.

One question: Did you look into ‘vehicle status’ and see what the pressure was once you got the warning?

I think 50 mph is not a reasonable speed for motorways, and they should try and devl runflats to cope with 60mph. At 50 mph, the inside lane is too dangerous, but I would prefer to have the choice of sticking to a motorway.

[Mr Run Flat]

Hi Pica Pica

I looked at vehicle status and tyre monitor however the relevant wheel was displayed as orange and others were green. No indication of what the pressure actually display numerically. Maybe I have an older system? 2012 reg

By the time we reached the service station it was completely empty, air was going straight through and out the hole.

[Ninja59]

Mr Run Flat said:

Hi Pica Pica

I looked at vehicle status and tyre monitor however the relevant wheel was displayed as orange and others were green. No indication of what the pressure actually display numerically. Maybe I have an older system? 2012 reg

By the time we reached the service station it was completely empty, air was going straight through and out the hole.

2012 will still be the ABS ring system.

I believe after 2014 it was the in wheel sensors, one element of that is it allows accurate pressure readings from each wheel (and with coding you can get tyre temperature as well).

Regarding tracking (technically it should be said "alignment"), as the tracking would only be for steering in reality the inner tyre wear is common across multiple cars these days as the level of negative camber has significantly increased across multiple manufacturers and models.

This negative camber is entirely within "factory specification" unlike what the tyre fitter said (have a look at the camber from factory specs of all recent BMW's and it will show a degree of negative), in fact it is deliberately engineered in to the vehicle as during corner the moment will be turned into a positive moment increasing grip and traction as well as being more "dynamic".

Whilst this may be an advantage for "handling" and "grip", the downside is the wear is not even across the tyre and the most significant wear is confined to the inner side of the tyre hidden from view. Driving in a straight line will in someways make things "worse" because the tyre is effectively not sitting 100% flat across the surface of the tyre.

One way of resolving this on the rear of most BMW's is to have it on an alignment a bring it as far "neutral" within factory specifications. You may find however that the initial turn in and during is not quite as enjoyable or the vehicle cannot take the same corner in the same conditions quite as quickly as a result. Note however that the front on any current BMW's tends to be more fixed than the rear.

Essentially the tyres are sitting more like this / \ instead of | | or even \ / (which would cause more outer tyre wear obviously!).

Note you may have some other issues such as toe in and out which can cause similar issues in certain circumstances. Ultimately get it to someone that knows about alignment and has a decent well maintained set of kit.

[anonymous-user]

Mr Run Flat said:

Hi Pica Pica

I looked at vehicle status and tyre monitor however the relevant wheel was displayed as orange and others were green. No indication of what the pressure actually display numerically. Maybe I have an older system? 2012 reg

By the time we reached the service station it was completely empty, air was going straight through and out the hole.

Direct and indirect systems. BMW used to offer both. Sounds like yours is the indirect, ABS based system not the direct, sensor valve type.

[K50 DEL]

Pica-Pica said:

I have run flats in a stepped set up. My left front alloy is badly Kerbed (my fault entirely). When tyres get worn down, I plan to get a new alloy, re-furnish the old one and keep that as a spare at home. The other alternative (for me) is drop to a square set up of cross climates, and keep a 5th at home as spare, and a can of goo in the boot.

One question: Did you look into ‘vehicle status’ and see what the pressure was once you got the warning?

I think 50 mph is not a reasonable speed for motorways, and they should try and devl runflats to cope with 60mph. At 50 mph, the inside lane is too dangerous, but I would prefer to have the choice of sticking to a motorway.

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!
I got a nasty one on the Bloody Foreland in NI last year, 55 miles on the runflat at low speed to the nearest place with a pair of (overpriced) ditchfinders that saw out my holiday and actually lasted 25k

[anonymous-user]

K50 DEL said:

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!
I got a nasty one on the Bloody Foreland in NI last year, 55 miles on the runflat at low speed to the nearest place with a pair of (overpriced) ditchfinders that saw out my holiday and actually lasted 25k

Between 2009 and 2014 there were two systems. Standard was the ‘Flat Tyre Warning’ system, ABS based, just advised on a puncture.

As an option on many models was the full TPMS, which showed individual pressure and, IIRC, temperature.

[Toltec]

Reminds me, I must check the state of the spare tyres.

[K50 DEL]

REALIST123 said:

K50 DEL said:

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!
I got a nasty one on the Bloody Foreland in NI last year, 55 miles on the runflat at low speed to the nearest place with a pair of (overpriced) ditchfinders that saw out my holiday and actually lasted 25k

Between 2009 and 2014 there were two systems. Standard was the ‘Flat Tyre Warning’ system, ABS based, just advised on a puncture.

As an option on many models was the full TPMS, which showed individual pressure and, IIRC, temperature.

It must depend on the model, my E84 X1 has no full TPMS option listed at all, for any trim level, though I know that E84s of the same era sold in the USA did have full TPMS

[Craikeybaby]

I got the red warning on my E87 yesterday 50 miles at 50mph rang a bell, so continued running my errands. When I got home I found that the offside rear was about 10psi down. I topped it up and used it as an excuse to take the sports car to work today.

I'll admit that with the runflats I have been lax about checking tyre pressures, I check much more regularly on previous cars.

[Mr Tidy]

K50 DEL said:

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!

I hope you never use any roads that I do!

Don't you have a tyre pressure gauge? If not don't you think you should?

Or can't you afford to visit a filling station and put some cash into the slot to check the pressure and re-inflate as required?

I bought a new foot pump in Tesco for £6 last week - it's not a big investment is it?

[K50 DEL]

Mr Tidy said:

K50 DEL said:

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!

I hope you never use any roads that I do!

Don't you have a tyre pressure gauge? If not don't you think you should?

Or can't you afford to visit a filling station and put some cash into the slot to check the pressure and re-inflate as required?

I bought a new foot pump in Tesco for £6 last week - it's not a big investment is it?

I think you might have got the wrong end of the stick fella, this was a topic about run-flats and I was commenting that the system in the early E84 BMWs is a basic one that doesn't actually display real-time pressures and although it tells you when a tyre loses pressure, it doesn't actually tell you which one.

In other words, the system's pretty useless and you need to rely on the usual methods of pressure gauge and pump - both of which I own and use regularly thank-you-very-much.

I'm really not sure how you manage to extrapolate your conclusions above from my previous post to be honest,

[anonymous-user]

K50 DEL said:

Mr Tidy said:

K50 DEL said:

Unfortunately the TPMS system fitted to EU BMWs of this vintage (I have a 2010 X1) don't actually give a pressure reading, nor do they even tell you which wheel is punctured!

I hope you never use any roads that I do!

Don't you have a tyre pressure gauge? If not don't you think you should?

Or can't you afford to visit a filling station and put some cash into the slot to check the pressure and re-inflate as required?

I bought a new foot pump in Tesco for £6 last week - it's not a big investment is it?

I think you might have got the wrong end of the stick fella, this was a topic about run-flats and I was commenting that the system in the early E84 BMWs is a basic one that doesn't actually display real-time pressures and although it tells you when a tyre loses pressure, it doesn't actually tell you which one.

In other words, the system's pretty useless and you need to rely on the usual methods of pressure gauge and pump - both of which I own and use regularly thank-you-very-much.

I'm really not sure how you manage to extrapolate your conclusions above from my previous post to be honest,

It did seem an odd response though I wouldn’t agree that the system is useless.

A direct system may give the pressure of each wheel but it won’t tell you how much tread is left or if there’s a screw beginning to make its way through the casing. Regular inspection is still worthwhile.

The ABS system will advise you of a serious drop in pressure before you notice the difference and it pretty easy to figure out which tyre it is.

[Locknut]

REALIST123 said:

A direct system ... won’t tell you ... if there’s a screw beginning to make its way through the casing. Regular inspection is still worthwhile. ..

Definately agree with that bit. Every now and then I jack up my car and rotate the wheels slowly so as to check the tyres. I have found all sorts of things stuck in them such as sharp grit, glass, wire, nails, screws etc. I remove them using a small screwdriver and I believe I have saved myself many punctures.

My theory is that very seldom does an object go straight through a tyre and cause an immediate puncture. Instead it gets stuck in the thread pattern and works its way through over the course of several weeks. If you get it in time you can save yourself a puncture.