Question 1

Where do I find the recommended pressure for my car?

Accepted Answer

On the sticker inside the driver's door jamb, on the fuel-filler flap, or in the owner's manual. Front and rear are often slightly different, and a fully loaded car typically wants 0.2–0.3 bar more.

Question 2

Why check pressure when the tyres are cold?

Accepted Answer

After 20+ km of driving, warm tyres read 0.2–0.4 bar higher, so specs assume cold tyres (parked 3+ hours). If they are hot, add about 0.3 bar to the target or wait. Never bleed air from hot tyres — you will end up underinflated.

Question 3

What are the dangers of underinflation?

Accepted Answer

About 0.3 bar low raises fuel use by ~0.3 L/100 km and wears the sidewalls and edges faster while overheating. At 0.5 bar low the casing can delaminate under load. Overinflation by 0.5 bar makes the ride harsh, reduces wet grip, and wears the centre of the tread.

Question 4

Why does the US use psi?

Accepted Answer

The US never went metric. One psi (pound per square inch) is the pressure of one pound over one square inch, equal to 0.0689 bar. US tyre gauges read in psi, Russian ones usually in bar or kPa — same pressure, different units.

Question 5

Should I fill tyres with nitrogen?

Accepted Answer

Nitrogen molecules are larger and leak more slowly, so pressure stays steadier — but the difference is tiny: about 0.05 bar lost in three months versus 0.1 bar with air. In practice, just check monthly. Some dealers offer nitrogen for free.

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