Does Tire Pressure Increase Automatically?
4 Answers
Tire pressure does increase automatically. During vehicle motion, tires are the primary friction components. As the car moves, continuous friction between the tires and the road surface causes tire temperature to rise, naturally leading to increased tire pressure. Therefore, if you need to check your car's tire pressure, it should be measured after the vehicle has been stationary for a period of time. Tire pressure values refer to static measurements: Since tires can only be inflated when the vehicle is stationary, the manufacturer's recommended tire pressure values inherently represent the static pressure after parking. If you release air while parked, allowing the vehicle to remain stationary until the tires cool down, the pressure will inevitably drop below the manufacturer's recommended value, requiring reinflation. Excessively high tire pressure compromises driving safety: Thus, when recommending tire pressure values, manufacturers already account for pressure increases during driving. Simply follow the manufacturer's inflation standards. Moreover, avoid overinflating tires, as this would cause pressure to rise excessively during driving, which clearly poses safety risks.
Having driven for over a decade, I'm all too familiar with tire pressure fluctuations. The air inside tires is as sensitive as a thermometer—it's common for pressure to spike after summer sun exposure. Last week on the highway, my TPMS suddenly alarmed, startling me into pulling over at the next service area. After parking for half an hour, the readings had returned to normal on their own. Seasoned drivers know temperature changes can cause over 0.3bar variation. I always keep a portable inflator in my car and check weather forecasts before long trips, deliberately lowering pressure by 0.1bar during heatwaves as a precaution.
Once during a family road trip with my kids, I had adjusted the tire pressure before departure, but halfway through the journey, the tire pressure warning light came on. A roadside mechanic checked with a gauge and found all four tires were overinflated. Pointing at the scorching asphalt road, he said: 'Tire friction raises temperature, increasing pressure by up to 10%.' Since then, I've made it a habit to measure tire pressure when the tires are cold in the morning for the most accurate reading. The difference is even more pronounced during seasonal changes between winter and summer. Last month when temperatures dropped, the tire pressure monitoring system showed a 0.2bar decrease overnight.
Last time during maintenance, I overheard the technician chatting and learned that tire temperature can reach 70 degrees when driving. I conducted an experiment: cold tire pressure was 2.3 bar, but immediately after highway driving it measured 2.6 bar. The auto shop guy told me tire pressure rises about 0.1 bar for every 11-degree temperature increase. Now I always have them check during car washes – turns out temperature affects pressure way more than I thought.
