Tire Blowout at 120km/hr: Control & Prevention
This post details my recent experience of a tire blowout at over 120km/hr, how to handle, and preventing blowouts. Blowouts occur when tires burst and rapidly loose air. This can be quite deadly but knowing how to handle a blowout if does occur, can greatly reduce the odds of having a ghastly accident. Howbeit, blowouts are best prevented because although you may know how to successfully handle a blowout, some “wicked” variable beyond your control may adversely affect outcome e.g. being surrounded by many cars during the blowout event!
My 120km/hr Blowout Experience: I was using a cab; Toyota Picnic, on the highway and the driver had maintained over 120km/hr along straight stretches of road. I had used same driver the day before and noted some thumping coming from one of the rear tires (wasn’t quite sure which one), the car also vibrated as it picked up speed. I suspected a broken tire belt, pointed these out to the driver who promised to have it looked at later but alas! At over 120km/hr the left rear tire blew! and the swerving started. The driver had started applying the brakes but instinctively I yelled “don’t brake, don’t brake” from the backseat. Long story short, with God on our side, holding the steering firmly, and compensating for the pull to the left, the car was safely brought to a stop off the road.
Handling Blowouts: Always remember never to slam on the brakes! If not, the drag from the blown tire coupled with the braking could send the car into a spin or initiate a rollover. A front blowout would usually cause a strong pull to the affected side. Its best to hold the steering firmly and compensate to the opposite side if need be. Rear tire blowouts will also cause swerving, but holding the steering firmly and guiding the car to a stop is best practice. Where possible, you may downshift to a lower gear to lessen speed. If possible hit the hazard lights.
Causes of Blowouts: One of the principal cause of tire blowouts is under-inflation. This leads to increase in friction between the tire and the road surface and consequently…more heat. This heat depending on duration and how high can lead to a breakdown of the structure of the tire leading to a blowout. For more on tire pressures see my earlier post: Tire Pressures 101: Getting it Right
A “good” tire may also have a blowout if punctured on speed. You should also avoid behaviors that also weaken tires generally e.g. having your tires pinned against a kerb, taking potholes on speed.
Cause of the index Blowout: From the account earlier its quite clear the left rear tire had broken belts. The thumping and vibrations were giveaways. However, why did the tire have a broken belt? If you wish to know more about broken tire belts please read this post I made earlier: Broken tire belts: meaning and symptoms.
My interaction with the driver showed the following:
- All tires were bought used.
- He did not know how to read manufacture date for tires.
- Did not seem to appreciate that tires expire.
Lastly, my inspection of the spare tire fitted to replace the blown one (this was a regular tire, not the compact temporary replacement tire) showed it was manufactured 7yrs ago! I could not establish the manufacture date of the blown-out tire because most readings on the sidewall were completely destroyed. Again, the remaining 3 tires had their manufacture dates on the inner surfaces of the tires and so were unreadable. However I believe the blowout was caused by the broken tire belts secondary to expiry.
The morale of this post is to promote knowledge on prevention and handling of tire blowouts. Do not compromise when it comes to replacing tires and aim to replace tires 3-4yrs after manufacture even if the threads are not worn. Do you have any more ways to handle blowouts that I’ve missed, hit the comments box.