Set your tyre pressure to the figure on your car’s door-jamb placard or in the owner’s manual, never to the maximum pressure printed on the tyre’s sidewall. The US government’s fueleconomy.gov says keeping tyres properly inflated can improve fuel economy by about 0.6% on average, and by up to 3% in some cases. Check pressure when the tyres are cold, and include the spare.
Key takeaways
- Use the driver’s door-jamb sticker or owner’s manual for the correct pressure. Michelin India says the placard may also be inside the fuel lid.
- Do not use the maximum pressure printed on the sidewall as your target.
- According to fueleconomy.gov, proper inflation improves fuel economy by about 0.6% on average and up to 3% in some cases.
- The same source says fuel economy falls by about 0.2% for every 1 psi drop in the average pressure of all tyres.
- Check tyres cold. Michelin India defines this as at least three hours after driving, or within 2 km of starting out.
- Michelin India recommends checking pressure once every two weeks and before long trips, and says the spare is part of the check.
- Pressure also matters for EVs, because rolling resistance affects range.
Where do you find the correct tyre pressure?
Your car’s manufacturer sets the right pressure, and it appears on the placard on the inside of the driver’s door, and on some cars inside the fuel lid. If you cannot find the sticker, check the owner’s manual. fueleconomy.gov says the proper pressure is usually found on a sticker in the driver’s door jamb or glove box, and in the owner’s manual.
The number moulded on the tyre sidewall is the maximum pressure for that tyre, not the right setting for your car. Michelin India explains that the same tyre can be used on different vehicles, so the vehicle maker determines the pressure that best balances load, ride, handling, rolling resistance and wear. If your car lists different front and rear pressures, set each axle to its own figure.
How much fuel do soft tyres waste?
Underinflated tyres have more rolling resistance, so the engine or motor has to work harder to keep the car moving. fueleconomy.gov says you can improve gas mileage by 0.6% on average, and up to 3% in some cases, by keeping tyres inflated to the proper pressure. It also says under-inflated tyres can lower gas mileage by about 0.2% for every 1 psi drop in the average pressure of all tyres.
These are US government estimates, and the 0.6% average assumes a vehicle that is under-inflated by about 10% across all tyres. Your own car may differ, so treat the figures as a guide and not a promise. The bigger reasons to maintain pressure are safety and tyre life, and fueleconomy.gov notes that properly inflated tyres are safer and last longer.
How and when should you check tyre pressure?
Check when the tyres are cold, because driving heats the air inside and raises the reading. Michelin India defines cold as at least three hours after the vehicle has stopped, and before it has been driven more than about 2 km. It also advises against letting air out of hot tyres, because the pressure will then be too low once they cool. Michelin India recommends checking tyres, including the spare, once every two weeks and always before extended driving. A simple routine looks like this:
- Find the recommended pressure on the placard or in the manual.
- Check all four tyres cold with an accurate gauge.
- Adjust each tyre to the figure for its axle.
- Check the spare as well.
- Refit the valve caps, which keep out dirt and moisture.
Should you fill tyres with nitrogen?
Nitrogen is not necessary, and regular checks matter more than the gas. Michelin India says nitrogen is simply dry air with the oxygen removed, and that its properties reduce pressure loss through the tyre’s natural permeability. It adds that leaks at the valve, the rim and elsewhere mean neither air nor nitrogen guarantees stable pressure, and that its tyres perform as intended with either, provided you follow the vehicle maker’s pressures. In other words, nitrogen can be a reasonable option if it is offered cheaply, but it does not replace the monthly habit. Whichever gas you use, keep checking the gauge.
What about the spare tyre?
The spare is easy to forget, and it can lose pressure while it sits in the boot. Michelin India says the spare should be checked along with the other tyres. If your car has a temporary space-saver spare, check the spare’s sidewall for its correct inflation pressure and its speed and distance limits, and follow the owner’s manual. Michelin India also recommends replacing tyres that are 10 years old or more from the date of manufacture, including spares, even if they look serviceable. Use the four-digit date code on the sidewall to find a tyre’s age.
Do EVs need the same attention?
Yes. An EV does not burn petrol, but it still has to overcome rolling resistance, so under-inflated tyres can reduce driving range. The correct pressure still comes from the car maker’s placard or manual. For EV owners the benefit shows up as more range per charge and a lower electricity bill. If you want to see what a kilometre costs, our EV vs petrol running cost guide explains the calculation.
FAQ
What is the correct tyre pressure for my car?
It is the figure on the placard in the driver’s door jamb, and for some cars inside the fuel lid, or in your owner’s manual. It is not the maximum pressure printed on the tyre sidewall.
How much fuel does correct tyre pressure save?
fueleconomy.gov says proper inflation can improve gas mileage by about 0.6% on average, and by up to 3% in some cases. It also says mileage can fall by about 0.2% for every 1 psi drop in the average pressure of all tyres.
How often should I check tyre pressure?
Michelin India recommends checking once every two weeks and before long trips, including the spare. Checking at least monthly is a sensible minimum if you cannot manage that.
What does a cold tyre mean?
Michelin India defines it as at least three hours after the vehicle was last driven, and before it has travelled more than about 2 km. Hot tyres read higher.
Is nitrogen better than air?
Michelin India says nitrogen can reduce pressure loss slightly, but that its tyres work with air or nitrogen as long as you follow the vehicle maker’s pressure. Regular checks still matter either way.
Does tyre pressure affect EVs?
Yes, because rolling resistance affects how far the car goes on a charge. Use the placard figure for your EV.
