What you need
- A tire pressure gauge (many air machines have one, but a separate gauge is a useful check)
- An air source: a gas station machine, a home compressor or a portable inflator
- Your car’s recommended pressure
Find the right pressure first
Look for the recommended cold pressure on the sticker inside the driver’s door jamb, or in the owner’s manual. Do not use the maximum pressure printed on the tire’s sidewall. Our tire pressure guide explains the difference.
Step-by-step: inflating a tire
- Park near the air source so the hose reaches every tire. Ideally, the tires are cold.
- Remove the valve cap from the tire and keep it somewhere safe.
- Press the gauge firmly onto the valve stem to read the current pressure. A hissing sound means the seal is not tight, so press again.
- Attach the air hose chuck straight onto the valve stem and add air in short bursts.
- Remove the hose and check the pressure again with the gauge.
- Repeat until you reach the recommended pressure, then replace the valve cap.
- Do the same for the other tires.
At a gas station air machine
Many machines let you set a target pressure, then fill and beep when they reach it. Others are manual. In both cases, it is wise to confirm the result with your own gauge, since station gauges are not always accurate. Some stations charge a fee, so have a card or coins on hand if needed.
If a tire is very low or flat, drive only a short distance, slowly, to reach air, or use a portable inflator or roadside help instead. See low tire pressure symptoms for how to judge it.
At home with a portable inflator or compressor
A portable inflator that plugs into your car’s power outlet, or a small home compressor, lets you top up whenever you like. Many have a preset function. Follow the manufacturer’s instructions, and still confirm the final reading with a gauge you trust.
If you put in too much air
Press the small pin in the center of the valve stem briefly, or use the release button on your gauge, to let air out in short bursts. Recheck after each release until you reach the target.
After inflating: TPMS light and recheck
If the TPMS warning light was on, it may go off after you drive for a while, depending on the car. Some vehicles have a reset procedure in the owner’s manual, and our guide to resetting your tire pressure sensor walks through it. If the light stays on, a tire may have a leak or a sensor problem, and a shop can check it. Also recheck pressures after a day or so, because a slow leak can show up as a falling reading.
Is 35 PSI a good tire pressure?
It is a common number for many passenger cars, but whether it is right depends on your vehicle. Use the placard value.
Does tire pressure affect gas mileage?
Yes. Underinflated tires increase rolling resistance, which can reduce fuel economy somewhat. Keeping tires at the recommended pressure is one simple way to avoid wasting fuel. See tire size and gas mileage for how tires affect economy more broadly. Temperature also shifts readings, as covered in how heat affects tire pressure.