Psi to kPa pressure unit conversion chart, convert psi tire pressure to kPa tire pressure.
The Optimum. Recommended pressure is usually between 30 and 35 PSI. That number indicates the minimum amount of air pressure needed to support your vehicle's maximum load-carrying capacity. Any less, and you'll see poor fuel economy and handling as well as premature wear from too much flexing and tire overloading.
So, let's say your manufacturer's recommend inflation level is 35 PSI, on one of those all-time hot August afternoons, your tire pressure could be somewhere near 40 PSI. Driving Here's another bit of math: Driving equals friction between the road and your tires equals heat equals…you guessed it…an increase in tire pressure.
Most passenger cars will recommend 32 psi to 35 psi in the tires when they're cold. The reason you check tire pressure when they're cold is that as tires roll along the road, friction between them and the road generates heat, increasing both the temperature and the air pressure.
If temperatures get particularly arctic, the rate at which tires deflate can be greater than the 1 psi per 10° rule of thumb. The low psi warning light pictured above was triggered on a -11° morning after a ~55° drop in temperature from the last tire psi adjustment. The tires pressure fell 8 psi overall due to that temperature drop.
PSI is the leader and original innovator in automatic tire inflation system for trucks, trailers, and fleets. Learn how a PSI system can pay for itself.