What’s the best tyre pressure?
23 AUGUST 2023
You regularly fill your car’s fuel tank… but when last did you check its tyres? Here’s how to check your tyre pressure – and how to determine the correct pressure for your car.That’s a good question, but it’s only half the right question. The “best” – or “correct” – tyre pressure varies from car to car. For your safety, and to prolong the life of your tyres, you’ll need to know what’s best for your particular vehicle – and you’ll need to check it regularly.
There’s an easy way to find out what the correct number is. It’s usually written on a sticker inside the driver’s door sill, in the cubby hole, inside the fuel filler cap, or under the bonnet. (Failing those, try the owner’s manual!).
For most passenger cars, the ideal tyre pressure will be somewhere around 2.2 bar (or 35 psi) when the tyres are cold. That number is measured by calculating the amount of air that’s been pumped into the inner lining of your tyre, with the value measured in bar pressure (or, sometimes, in pounds per square inch, or psi). The stipulated value is determined by your vehicle’s load and driving speed, and not – despite what your know-it-all nephew read on the Internet – by the size or type of tyre.
We work on bar pressure in South Africa, but if ever you need to convert psi values, here’s a quick guide:
1.70 bar = 24 psi
1.80 bar = 26 psi
2.00 bar = 29 psi
2.20 bar = 32 psi
2.30 bar = 34 psi
2.50 bar = 36 psi
Remember to check your car’s tyre pressure every time you fill up at the petrol station. If you don’t check them regularly, they could become under-inflated, which will cause excess wear and tear on the inside and outside edges of the tread. Over-inflated tyres, meanwhile, have a much narrower contact patch with the road, which can lead to poor braking distances and loss of traction on the road.
You’ll need to change your tyre pressure if your car is fully loaded – so if you’re packing for a family holiday, be sure to buy a tyre pressure gauge for at-home checks as well!