Surveying over 500 vehicles in Tesco supermarket car parks in Manchester, the study revealed that around 27.5% of cars had at least one tire between 7 and 14 psi (14.5 psi is around 1 bar pressure), which is deficient when given the manufacturer’s recommendations. And a little over 12% had over 14 psi, but still under-inflated tires. Michelin and Kwik Fit consider tires with this little pressure to be dangerous or very dangerous.



Driving with pressures this low affects the behavior of the vehicle and compromises safety, even endangering lives. Insufficient pressure can collapse the casing which, as well as making for uncomfortable driving, increases braking distances, weakens vehicle traction, raises temperatures and, in the worst cases, can blow the tire. Inversely, too much pressure (a rarer situation) will reduce grip and lifespan and increase irregular wear of the tire.



The study also shows the financial repercussions of under-inflated tires. Driving with low pressure tires (7 psi or a little less than 0.5 bar) generates a fall in performance of 0.42km per liter of fuel used, the study explains. In other words, to cover the same distance, an under-inflated tire will consume more fuel. This represents 17.2 extra liters of fuel every year, for an average annual total of 12,000km. Or 25 to 30 euros extra at current fuel prices. So every year, in a town like Manchester, drivers unnecessarily spend over 2 million pounds on fuel, nearly 2.2 million euros. Not forgetting the unnecessary CO2 emissions.




Michelin does everything possible to ensure the safety of its customers, including those whose tires are under-inflated and to remind people of the importance of following manufacturer recommendations. However, it is everyone’s individual responsibility too: drivers, passengers, family and friends.

"Checking tire pressure is as important as checking the depth of the tread."

Advertising Director at Kwik Fit

He wants every driver to remember their tire pressure and check their tires regularly.

We would like all drivers to check their tire pressure. It’s important for the environment and your wallet, but even more important in terms of safety!

Jamie McWhir, Technical Manager at Michelin UK

Bad tire pressure...the 5 dangers:

Low or high, tire pressure can have different effects on the safety of your vehicle:


  1. Durability
    Driving on under-inflated tires reduces their endurance, causes faster degeneration and even a sudden puncture.
    Low pressure > 0.5 bar = DANGER (risk of puncture)
  2. Braking
    Under-inflated tires increase the vehicle’s braking distance
    Low tire pressure = longer braking distance
  3. Road handling
    With low tire pressure, precision driving for corners is altered
    Low pressure = altered road handling
  4. Fuel consumption
    Low tire pressure increases the tire’s roll resistance and therefore fuel consumption.
    Low tire pressure = higher fuel consumption
  5. Aquaplaning
    If a tire is only at 30% of the recommended pressure, there is an increased risk of aquaplaning.
    Low tire pressure = risk of aquaplaning



Use the pressure recommended by the manufacturer as it is adapted to your vehicle. You will optimize its performance and your safety. A tire loses pressure naturally and this varies depending on the temperature. We therefore recommend checking your tires at least once a month and always before a long journey. Remember to also check the pressure in the spare wheel. And remember that recommended pressure levels are often different for rear and front tires.

Where is the information I need?

The correct pressure for your car tires is usually in the car’s manual. It can also be written inside the vehicle, on the inside of the driver’s door, in the fusebox or on the inside of the fuel tank.



Usually, two different pressures are indicated:

  1. For “regular” driving conditions
  2. For a loaded vehicle (carrying many people or a heavy extra load)

To check your tire pressure, you need a manometer or standard tire pressure equipment. Most gas stations and tire dealers have this equipment (often for use free of charge).
* Psi, or pounds per square inch, is the standard measurement for tire pressure in the United Kingdom.


Research and Development Director, specialized in tire assessment



How is Michelin working on the safety of under-inflated tires?

In anticipation of people driving with low tire pressure, Michelin imposes design rules which help the tire maintain a satisfactory safety level, even under these conditions. However, low tire pressure means deterioration; road handling, comfort, roll resistance and durability will suffer.

How do you approach these issues with manufacturers?

Tires are designed for a specific use (load, pressure, speed, etc.; see their ETRTO reference). The vehicle manufacturer’s definition of this use takes into account tire safety performance. In collaboration with the tire company, the car manufacturer defines a pressure range for a given vehicle within which the tire will perform best (road handling, comfort, etc.).

Is it Michelin’s responsibility to inform drivers of the risks of driving with low pressure tires?

For Michelin, it is always necessary to remind drivers that tires should be used at the recommended pressure. Tires are designed to meet regulatory standards defined by governments, standards which define minimum safety conditions for users. The load and pressure conditions for a given tire are within this regulatory framework. Remember that Michelin is a driving force behind the generalization of pressure surveillance systems with the MICHELIN Track Connect device; it warns the driver if his tires are not within the recommended pressure range.

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