How to Use the Tire Pressure Fuel Loss Calculator
Underinflated tires increase rolling resistance, forcing your engine to work harder and burn more fuel. The US Department of Energy estimates you lose about 0.2% MPG for every 1 PSI below the recommended pressure. This calculator shows exactly how much money you're losing at your current pressure levels.
Finding Your Recommended Tire Pressure
Your vehicle's recommended tire pressure is listed on a sticker inside the driver's door jamb or in the owner's manual. This is typically between 32–38 PSI for passenger cars and 35–45 PSI for SUVs and trucks. Do not use the maximum PSI molded on the tire sidewall — that's the tire's limit, not the ideal operating pressure.
Beyond Fuel Economy: Safety Impact
Under-inflation also reduces handling precision, increases braking distances, and causes uneven tread wear that shortens tire life. At high speeds, severely underinflated tires can fail catastrophically. Proper inflation is one of the easiest and most impactful vehicle maintenance tasks.
Frequently Asked Questions
You lose about 0.2% in gas mileage for every 1 PSI drop below the recommended level. If all four tires are 10 PSI low, you could lose about 2% in fuel efficiency — costing you real money over a year.
Check the sticker inside your driver's door jamb or the owner's manual. Do not use the maximum PSI on the tire sidewall — that is the tire's maximum capacity, not the recommended pressure.
Check at least once a month and before long trips. Tires lose about 1 PSI per month naturally, and pressure drops 1 PSI for every 10°F drop in temperature.