The correct tyre pressure is the amount of air a tyre should hold to carry the car safely and let it steer, brake and ride as designed. The key point catches many people out: that figure is set by the vehicle manufacturer, not by the tyre, and it is the single number to work to.
Set by the car, not the tyre
Every car is given a recommended pressure based on its weight, how much it is built to carry, and how its suspension is tuned. That is why two cars wearing the same size of tyre can need different pressures.
The number moulded into the tyre sidewall is a different thing entirely: it is the tyre's maximum pressure, set by the tyre maker, and it is usually well above what the car actually needs. Inflating to that figure would leave most cars badly over-inflated. The pressure to use is the one the car maker specifies.
Always a cold figure
Recommended pressures are cold pressures. As a car is driven, the air inside the tyres warms and expands, and the pressure rises by several PSI. The manufacturer's figure assumes a cold tyre, one checked before driving, or after the car has stood for a few hours, so a reading taken on warm tyres will sit a little high and should not be "corrected" down to the placard figure.
This is why the routine for checking pressure always starts with cold tyres.
Typical figures, and the variations
For a typical car, recommended pressures usually fall somewhere between about 28 and 36 PSI (roughly 1.9 to 2.5 bar), though heavier vehicles and EVs often run higher. Two common variations matter:
- Front and rear can differ, with one axle set a little higher than the other
- Normal and laden figures are usually both given, a higher pressure for a full load of passengers or luggage, or for towing
Pressure is given in PSI (pounds per square inch) and bar, and sometimes kPa; one bar is about 14.5 PSI.
Why the right figure matters
Correct pressure is where grip, braking, fuel economy, ride and tyre life are all at their best. Stray below it and the tyre runs hot, drags and wears its edges; stray above and the centre wears while grip and comfort fall. The recommended figure is the balance point the manufacturer settled on, which is why new tyres are inflated to that spec rather than to a round number when they go on, the figure a fitter sets a fresh set to when an order from an online tyre shop like Tyres.co.uk is fitted.
From the workshop: the classic mistake is reading the big number off the sidewall and pumping to that. That figure is the tyre's ceiling, not the car's target. Always work to the door sticker or the handbook.
Sources and accuracy. The figures and principles here reflect manufacturer guidance at the time of writing and vary by vehicle; the car's own placard and handbook are the definitive source. If anything here looks wrong, get in touch and we will check it and put it right.
Common questions
What should my tyre pressure be?+
It depends entirely on the vehicle, not the tyre. The car maker sets a recommended pressure, usually somewhere between about 28 and 36 PSI for a typical car, and it is shown on a sticker on the car and in the handbook. That figure, not the number on the tyre, is the one to use.
Is the pressure on the tyre sidewall the one to use?+
No. The figure moulded into the tyre is its maximum pressure, set by the tyre maker, and is usually well above what the car needs. The correct working pressure is the lower figure the vehicle manufacturer specifies for that car.
Why is tyre pressure measured cold?+
Because driving heats the air inside the tyre and raises its pressure by several PSI. The recommended figure is a cold pressure, measured before driving, or after the car has stood for a few hours, so that the tyre carries the load and handles as intended.
Should the front and rear pressures be the same?+
Not always. Many cars specify a slightly higher pressure at one axle, and most give a separate, higher set of figures for a full load. The placard and handbook list each, so it is worth matching the right figure to how the car is being used.