View Full Version : What could have happened next?

13th Sep 2011, 21:12
Driving on a motorway, early morning, quite fast and not much traffic, when a Saab pulled up beside me as I was slowing down on the approach to merging onto a new motorway.

Passenger was gesticulating quite wildly whilst I was trying to lip read what she was saying to me. Turns out my rear tyre was buggered.

I managed to lean forward to catch a glimpse of it in the wing mirror, and almost had a heart attack, it was as flat as a pancake.

I duly pulled into an emergency lay-by and called the breakdown service, meanwhile the traffic cops pulled up and asked if I was ok (female alone, etc).

Anyway, long story short, my rear tyre was very flat indeed, another was almost on its last legs, and a third was still ok, but getting towards the not ok. It appears I have driven over 'something' - there was a very small puncture mark.

400 quid and three new tyres later I set off to continue my 350 mile round trip. I drive a 2.4 Volvo S80, which is quite a heavy car, but extremely comfortable for long distance motorway driving.

My question is, if that good lady had not flagged me down, what would have happened to my tyre/wheel had I continued driving oblivious to the fact, and why didn't I feel anything?

It did shake me up somewhat, but I've learned my lesson, always check the tyres prior to setting off!

Lon More
13th Sep 2011, 21:16
what would have happened to my tyre/wheel had I continued driving oblivious to the fact, and why didn't I feel anything?

1)Bang! Thump! Ambulance.

2)Volvos are designed to insulate those inside as much as possible from the outside world. Not for nothing the car of choice for Crash Test Dummies.:E

13th Sep 2011, 21:18
When I started reading I thought you were going to become a victim of the folks who drew up alongside.

Glad it wasn't anything like that.

Be interesting to know how your tyres go to be in such a state. It's possible they've been low for a while... You'd not notice a slow change.

13th Sep 2011, 21:24
Sods law, the one tyre that had was flat and seriously knackered was one of two that were fine. it was the other two that need replacing (plus the flat one = 3)

Don't know why, but I seem to go through tyres pretty fast, and at almost 150 each, it hurts. I've had the tracking checked showing no problems.

I used to do a lot of long distance motorway driving, but this past 12-18 months, mostly just local trips, so hopefully the wear and tear on the tyres will decrease.

13th Sep 2011, 21:35
As a (now retired) vehicle test engineer, I am surprised by the number of cars that I see with soft tyres.
Whenever possible I leave a note wedged in the driver's door pointing out the danger of driving with soft tyres (risk of overheating with possible carcass failure as well as possible instability when cornering) and suggesting a trip to a garage or tyre depot.

In your case (travelling in a straight line at speed) it would have eventually 'exploded' (either due to carcass failure or loss of tread) and your stability would have been affected - possibly putting you into a spin beyond your control with contact with other vehicles or the barrier.

It's worth checking your tyres visually every time you approach your car to start a journey (even a short one) as you can tell simply by looking if the pressure is dangerously low.

Driving any distance on a soft tyre will damage the casing of the tyre (even if it has lots of tread) and you will have to replace or risk it failing (maybe catastrophically) at some future time (maybe less conveniently than when you are able to stop by a filling station and inject some air).

flying lid
13th Sep 2011, 21:35
This is what a traffic cop once told me

Have a tyre blow out at up to 70mph and you have a good chance of survival

Have a tyre blow out at 80mph and up your chance of survival is slim.


13th Sep 2011, 21:55
There are some cars that are better than others for stability with a blowout - and some drivers better capable of coping with the event, but I have known of Police fast-patrol drivers (who train for such eventualities) ending up in the barrier.

I was trained by (then current) Police advanced driving instructors before I started my career as a test engineer, and I have many thousand miles experience of fast driving (sometimes verging on the wreckless) but, so far, have never had to cope with a tyre burst.

It is sometimes possible to sense an underinflated tyre when cornering at low speed as the car handles differently, but, as suggested, if the loss of pressure was gradual you might not notice the change.

Best way is to check visually before setting off (you don't need to use a pressure gauge - though it will be better if you can buy one and learn how to use it).

Even if you only look at your tyres when you fill with fuel it is better than never looking.

13th Sep 2011, 22:27
Forgotten Stinger from the previous evening's jolly japes??

A Stinger was my first thought as well.. :rolleyes:
Well, either that or you drove past a mad man with a nail gun!:E


PPRuNe Dispatcher
13th Sep 2011, 22:32
Some years ago my nearside rear suffered a totally catastrophic blowout when I ran over a chisel which I later found embedded in the wheel hub. I was overtaking another car at the time and was travelling at high speed. The tyre was completely destroyed, there was a 1mm deep mark in the tread of the front tyre where I'd run over the chisel and that had probably fired it into the rear.

By not touching the brakes and by keeping the car straight which wasn't particularly difficult, I coasted to a halt without any problems. I'd been trained to drive by a class 1 police instructor, and part of the course was coping with "oh shit situations..." So if you don't panic, a blowout isn't necessarily anything to panic about. But touching the brakes might have made life just a bit too interesting....


13th Sep 2011, 22:38
you can tell simply by looking if the pressure is dangerously low.

Not on my car. The low profile tyres always look nearly flat to me.

Maybe I should go back to cross plys?

13th Sep 2011, 23:06
I have many thousand miles experience of fast driving (sometimes verging on the wreckless)

So quite a few ended up with a wreck? :p

My old BSA motorbike once blew its rear tyre at about 80 mph . A bent three inch nail penetrated the tyre and instantly "nibbled" away the inner tube. On a spoked wheel this means very rapid loss of pressure. I was very lucky to keep the bike upright because one bead of the tyre was off the rim and the bike was going partly sideways along the edge of the grass verge. I think my introduction to motorcycle riding, off-road mud plugging in my pre teen years, helped me know what to do when the back end wasn't in line with the direction of travel. I also had a passenger.....but she wasn't at all impressed.

14th Sep 2011, 04:10
At least you didn't take a corner and have the tyre bead separate from the rim. Then the rim could have dug into the road, etc...

In assume the problem was in a rear tyre. I drive a 1984 Mercedes 230E (quite a heavy car, something like a well-made Volvo :E ) and had a slow leak in a rear tyre. It's not easy, with the weight and the power steering, to pick up the tell-tale soggy feel caused by the flat(tening) tyre. The walkaround is a good idea.

14th Sep 2011, 04:15
I had a tire blow on my BMW 5 series many years ago... the only way I noticed was bits of rubber flinging off in my side mirror as the tire continued to disintegrate.

I stopped twice (second stop quite quickly after), as I did not notice the tire on the first look see (to be fair I thought it might have been the plastic stripe on the side panels, so was not looking at the tire.

And that is when I learned about tires being rated for a certain speed (240kph), which I had been exceeding for about 4 hours....

Thankfully it was not a front wheel; and I learned from that about being young and foolish...

14th Sep 2011, 04:34
A tyre slowly going flat won't blowout like a fully inflated one receiving a fatal injury to the carcass, that results in instant destruction. That is indeed a dangerous occurrence, and has often resulted in vehicle loss of control and serious accidents.

A nearly-flat tyre will eventually give up the ghost through vastly-increased heat buildup, and shred itself... and then you have rim contact with the road, resulting in vehicle imbalance as far as weight-shift goes... and poor response to steering input.

By far the most dangerous aspect of tyres running low on pressure (and the driver not knowing), is when a sharp curve is encountered, or a sharp steering input, such as a swerve, is involved.

With a half-flat tyre, this results in excessive vehicle movement, either severe understeer or severe oversteer.
A half-flat front tyre will result in severe understeer, meaning that more steering input is required to obtain the same response as compared to a normally-inflated tyre.
A half-flat rear tyre results in severe oversteer, which often leads to loss of control as the rear swings out violently.

In severe cases, a swerve or sharp cornering with a half-flat tyre will make the tyre come right off the rim. This will also often result in loss of vehicle control, unless the driver is exceptionally alert, has fast relexes, and has substantial driver skills.

A half-flat front tyre is usually felt in "spongy" steering response. A half-flat rear tyre is more difficult to detect, and is usually only picked up by increased rear-of-vehicle movement when steering corrections are carried out.
A good driver is alert to tyres "feeling funny", and will stop and investigate.

I've had blowouts at speed, and they are ar$e-puckering moments. Many hundreds of thousands of kms of high speed country driving, mostly on gravel roads gave me a good grounding in vehicle control... along with quick reflexes.
The most frightening was a blowout in a LH front tyre in a tandem-drive truck. The drag created by the shredded tyre pulled me off into the scrub, despite doing my best to keep the truck straight and on the road.

Fortunately, no damage resulted, but I sure needed a change of underwear. I pride myself on good vehicle maintenance and careful operation, but like all mechanised devices, there's always one waiting to bite you if you aren't alert.

im from uranus
14th Sep 2011, 04:42
Just recently part ex'd my 2002 S80 for a nice 2008 C70 (T5). On the A34 recently the car behind flashed me, I was doing about 85mph at the time, roof down, loads of noise etc. I looked behind to see smoke! Pulled over and my rear nearside tyre was fooked! If the guy behind hadn't flashed I'd have lost the wheel too! I didn't even feel it, 18" alloys, low profile, and it still handled well. Maybe too well.....

B Fraser
14th Sep 2011, 06:37
I once had a rear tyre on a Porsche 930 Turbo destroy itself while travelling at what the French call "Grande Vitesse". I kept off the brakes and made it onto the grass verge ...... which duly caught fire. I moved the car rather sharpish which only caused more of the grass to catch fire etc etc.

Fortunately I was on a straight road, had I lost it on a bend then Isaac Newton would have been steering me straight to the scene of the accident.

14th Sep 2011, 06:40
Onetrack's mention of tires moving around on the rim is true. As kids we used to lie on the bonnet of the ute to watch the front wheels & tires directly underneath. The amount the radials at low pressure would move out of centre is astonishing if you haven't seen it before. Not so the crossply tires.

I've had several blowouts and the lesson I learnt was to slow down slowly; if you quickly step on the brakes you are courting danger. In my opinion the biggest risk of instability is with trailers, particularly those with a single axle; and worse still caravans. I have tank-slapped my way across two lanes and back recovering from a blowout on a heavily loaded trailer. Had I used the brakes I feel certain I would have bent things and involved others.

Specialist off-road tires for motorcycles can be bought with ribbed sidewalls. With rimlocks they can be run at speed completely flat with only slightly reduced handling issues for many hundreds of kilometres with no damage afterward; done it. Vulcanduro(?) comes to mind. Road tires are a different story; I've often wondered if a tire on your 310kph superbike lost air what would happen.

14th Sep 2011, 11:10
Hello Helol,
For the price of one of your tyres, you could buy one of THESE (http://www.autocaress.co.uk/acatalog/Tyre_Pressure_Monitore_System__TPMS__.html) (or something similar, it's not the only one on the market). You can keep it when you change your car so it is a lifetime investment, and after it has saved you one tyre you're in profit!. Or you could put it on your Christmas present list.

No connection with any company producing these, just happened to come across them last week when I was at a test track checking out something else entirely.


PS for those of us who haven't taken any advanced driver training, a session on a skid pan is well worth the investment and will give you at least a chance of surviving high speed "offs".

Lon More
14th Sep 2011, 11:20
you could buy one of THESE (or something similarStandard fitment these days on many cars but was surprised to find it an option on the new Range Rover. re-considering the purchase now I'm totting up what I consider esential and it's all extras. :(

SMT Member
14th Sep 2011, 11:21
I'm surprised anyone would change only 1 or 3 tires. Don't know what the rules are around your places, but where I'm at you must have identical wheels mounted at the front and back ends. Which makes nothing but sense if you ask me.

I've had a couple of punctures in my time, both happened driving a car with run-flats. Run-flats can't be repaired, so every time it happened I bought two new ones and had both of the new ones fitted either to the front or back, never at opposite ends.

Perhaps I'm just being overtly anal, but when you spend a considerable amount of time blitzing the Autobahn at speeds north of 200 kmh, the last thing I want to worry about are the tires. It's only money after all, and my life is worth quite a bit more than the extra 180 Euro it cost to replace two tires rather than one..

14th Sep 2011, 11:22
A chap I worked with drove a Volvo and he was very careful about all aspects of driving IAM . He went out to the carpark one lunch time and notice a flat tyre on his car and was convinced it must have just happened BUT when the chap came to fit a new one he said the car had been driven for some time on a flat tyre !

14th Sep 2011, 12:04
Word of warning. If this happens here in the North of Spain, particularly on the motorway from La Jonquera to Barcelona, it's more than likely an attempt to rob you. If it happens when you are driving around Barcelona, likewise. Lock all doors, pull off road, sit in car until the South Americans or Rumanians (it always is) who are telling you the tyre is flat have driven off. Then get out to check, being extremely vigilant. If anyone approaches you while you are checking car, consider using violence against them unless they are Holy Sisters or garbed as Priests. Police will ALWAYS approach you showing ID but still be careful as there are "fake police" about.

Note: the above applies to cars with foreign, i.e., non-Spanish plates, or cars with Hire Car stickers in the windows.

As much as I love living in Catalunia I can't emphasise enough: Barcelona and the environs is a very dangerous area for tourists.

18th Sep 2011, 23:03
Interesting read.

I had a tyre go on me (80ish mph outside lane of M40) a couple of years ago, first I knew about it was when I heard metal screeching. I don't quite remember crossing the other two lanes but effectively dumped the car on the hard shoulder where I spent 5 minutes searching the rear of the car to find out which bit of the exhaust I was missing as I was convinced that that must have been the problem given the level of noise.

I was on the phone to my business partner at the time when he asked if I'd looked at the front of the car, I was about to tell him not to be stupid as I couldn't think of anything else of a sizeable metallic nature that could have come off when I noticed my front off-side tyre wasn't there any more and the wheel had a rather strange flatish look to it at the bottom.

I hadn't heard anything or felt any difference in handling before the event and it really didn't cross my mind that it might have been a blowout, which in hindsight probably saved me a lot of trouble as I was too preoccupied with trying to work out what had gone wrong to hit the brakes in panic. I don't think I actually braked until I was on the hard shoulder. I dread to think what could have happened, to me or the poor b*gger behind me who probably narrowly escaped a facefull of rubber.

The bastard thing was the tyre was less than 48hrs old - first time in the car's life I'd fitted brand new tyres rather than pre-worns as well! :rolleyes:

I don't like to think about the consequences of the same thing happening to the bike :uhoh:

18th Sep 2011, 23:46
Blew a near front tyre at about 80 km/h, in a Datsun 180B SSS and fortunately managed to stay relatively straight and upright by not touching the brakes until almost stopped.

Just as exciting is blowing a tyre (front or rear) on a tandem bicycle at about 50 km/h. I've done both at different times, and found it harder to keep control when the rear blew. Even more exciting for the blind bloke on the back!

19th Sep 2011, 00:30
Engineering dynamics are such that a rear tyre failure will result in loss of directional stability and the vehicle will spin (unless a skilful and 'lucky' driver can apply appropriate steering correction - and even then it is probably beyond even the most experienced test driver).

If you want to test this theory, obtain a model car and a sheet of glass or some smooth, shiny low-coefficient material.
Using blutack or a rubber band 'lock' the rear wheels (or just one will do) then increase the angle of the sheet until the toy car slides down the slope.
Repeat with a front wheel locked (or reverse the direction of the model) and you will discover that a rear wheel lock will always initiate a spin whilst a locked front wheel will continue in a straight line.

Of course, if your real vehicle is fitted with an electronic stability control system you stand a better chance of avoiding loss of control after a tyre blowout.

19th Sep 2011, 20:17
Had what I thought a puncture recently and went to get it fixed to find that the Alloy on the inside had buckled which meant Tyre was losing pressure ever so slowly. Probably a pothole somewhere.

Tyre place chucked on the spare and had the alloy fixed at one of those repair places and matched the spare tyre with new one and put the used tyre in as a spare so least now have 2 new ones on the front.

Someone told me it doesn't matter whether Fronts are same make but prefer not to try that one.

Good advice on here about driving with blowouts:ok: thanks