Michelin and Kwik Fit technicians have found that 40% of cars they checked had at least one tyre that was “dangerously” or “very dangerously” underinflated.

Michelin classifies tyres that are between 7psi and 14psi below the manufacturer’s recommendation as “dangerously underinflated”, while 14 psi or more is deemed to be “very dangerous”.

Technicians inspected more than 500 vehicles in Tesco car parks around the UK and found 28% of cars had at least one dangerous tyre, with 12% having at least one very dangerous tyre.

“Driving around on underinflated tyres costs money and it can cost lives,” said Jamie McWhir, technical manager for Michelin in the UK.

“We wanted to team up with Kwik Fit to encourage motorists to check their tyre pressures regularly. It makes sense from a cost and environmental point of view, but more importantly it’s critical for the safety of the vehicle, its passengers, other road users and pedestrians.”

Running a car with tyres underinflated by 7psi decreases fuel efficiency by about one mile per gallon.

Roger Griggs, communications director at Kwik Fit, said: “Checking tyre pressure is as important as checking tread depth, as tyres at the wrong pressure will compromise handling, grip and braking. As well as the significant safety issues, incorrectly inflated tyres will hit drivers in the pocket through excessive fuel consumption and increased tyre wear.

“It’s worth reflecting on the fact that a car’s tyres are the only thing to connect it with the road and we urge motorists to check their air pressure, tyre condition and tread depth every fortnight.”