The Real Cost of Driving on Under-Inflated Tyres
Driving on under-inflated tyres costs you in three ways: it increases rolling resistance and wastes fuel, it wears the tyre edges so you replace tyres sooner, and it builds up heat that raises the risk of a dangerous blowout. A simple monthly pressure check prevents all of these costs for free.
The fuel cost
Under-inflated tyres have a larger contact patch and flex more, which increases rolling resistance. The engine has to work harder to keep the car moving, so it uses more fuel.
Across a year of driving, soft tyres can noticeably add to your fuel bill. Keeping pressures correct is one of the simplest ways to improve fuel economy at no cost, which matters more than ever with today's fuel prices.
The tyre cost
Low pressure changes how the tyre meets the road, concentrating wear on the outer edges of the tread. The tyre wears out faster and unevenly, so you buy replacements sooner than you should.
Given the price of a set of tyres, premature wear from running them soft is a genuine and avoidable expense, often amounting to losing many thousands of miles of useful tread.
The safety cost
The most serious cost is to your safety. Under-inflated tyres flex more and build up heat at speed, which can lead to a sudden blowout, especially on a hot motorway.
- Longer braking distances and reduced grip.
- Poorer handling and stability, especially in corners.
- A higher risk of dangerous high-speed failure.
Over-inflation has its own costs
It is worth noting that too much pressure is not the answer either. Over-inflated tyres wear out the centre of the tread prematurely, give a harsher ride, and reduce grip because less of the tread is in contact with the road.
The goal is simply the correct pressure for your car and load, found in the handbook or on the door-sill label, not as high as possible. Correct pressure keeps the whole tread working, which is best for wear, grip, comfort and economy alike.
Slow punctures and recurring drops
If one tyre keeps going soft, the cause is usually a slow puncture from a nail or screw, a faulty valve, or a poor seal where the tyre meets the rim. Repeatedly topping it up masks the problem rather than fixing it.
Many slow punctures in the tread can be safely repaired for far less than a new tyre, so it pays to have a recurring low tyre checked promptly. We will find the cause and either repair it to standard or advise replacement if the damage is not safely repairable.
The easy fix
All these costs are prevented by the same simple habit: check your pressures at least once a month and before long journeys, when the tyres are cold, and top up to your car maker's figure.
If your tyre pressure warning light keeps coming on, you may have a slow puncture worth checking. Pop into our Norwich garage and we will check your pressures and tyres, with no obligation, so a small problem never becomes an expensive one.
Frequently Asked Questions
Do under-inflated tyres use more fuel?
Yes. Low pressure increases rolling resistance, so the engine works harder and burns more fuel. The effect adds up over a year of driving. Keeping your tyres at the correct pressure is one of the simplest and cheapest ways to improve your fuel economy.
How does low tyre pressure affect safety?
Under-inflated tyres flex more and build up heat, which raises the risk of a sudden blowout, especially at motorway speeds in warm weather. They also lengthen braking distances and reduce grip and stability. Correct pressure is important for safe handling and braking, not just economy.
How often should I check tyre pressure to save money?
Check at least once a month and before long journeys, with the tyres cold. This catches gradual pressure loss and slow punctures early, preventing the fuel waste, premature wear and safety risk of running soft. It takes a couple of minutes and costs nothing.
Is over-inflation as bad as under-inflation?
It is also undesirable, just in different ways. Over-inflation wears the centre of the tread, gives a harsher ride and reduces grip because less tread touches the road. Neither extreme is good; the aim is simply the correct pressure for your car and load, no higher and no lower.
Why does one of my tyres keep going flat?
A single tyre that repeatedly loses pressure usually has a slow puncture from a nail or screw, a faulty valve, or a poor rim seal. Repeatedly topping it up only masks the issue. Many slow punctures can be safely repaired for far less than a new tyre, so have it checked.
Book With Norwich Tyres & Auto Service
Need a hand from a real, independent Norwich garage? Call 07933 900901 or pop into Ber Street, NR1 3ES. Same-day tyre fitting is available on most common sizes, with free parking on site.