Tyre pressure for trailers

The tyre pressure of your trailer plays a key role in safety and tyre wear.
Too much or too little pressure can cause the tyres to wear prematurely—or worse, lead to an accident. That’s why it’s essential to check the tyre pressure regularly. In this blog, we’ll explain how to do that and what the correct pressure is.

Tyre pressure in Bar or PSI

Tyre pressure refers to the air pressure inside your trailer’s tyres. It’s expressed in bar or PSI (Pounds per Square Inch). This pressure is usually higher than that of a car tyre, which makes sense because trailers often carry heavier loads. The ideal tyre pressure depends on your tyre size, trailer load capacity and the maximum speed you'll be travelling at.

Conversion tool:
1 bar = 14.5038 PSI
1 PSI = 0.0689 bar

Always measure tyre pressure when the tyres are cold.
If you don’t have a pressure gauge at home, visit the nearest petrol station—ideally within 5 km—for the most accurate reading.

How to find the right tyre pressure for your trailer

The maximum tyre pressure is often printed directly on the sidewall of the tyre. You can also find it in your trailer’s manual. Most manuals include a full chart where you can match tyre size with the recommended pressure based on load and speed.

Let’s take an example: tyre code 195/50R13 104 N

Tyre size:

  • 195: Tyre width in millimetres
  • 50: 50% of the tyre width = 97.5 mm sidewall height
  • R: Radial construction
  • 13: Rim diameter in inches

Pressure rating:

  • 104: Load index of 900 kg
  • N: Maximum speed rating of 140 km/h

General Guidelines for Trailer Tyre Pressure

The second part of the tyre code determines the pressure based on load and speed. Here are some common references:

Load Index:
90 (600 kg) | 93 (650 kg) | 100 (800 kg) | 103 (875 kg) | 104 (900 kg)

Speed Index:
J (100 km/h) | K (110 km/h) | L (120 km/h) | M (130 km/h) | N (140 km/h)

In short: the correct tyre pressure depends on the tyre type, how much your trailer is loaded, and your driving speed.
Check the user manual to determine the recommended bar or PSI value. Most trailer tyres require between 3.0 and 4.5 bar, while smaller tyres may need up to 5.0 to 6.0 bar.

Why Tyre Pressure Matters for Your Trailer

As we briefly mentioned, maintaining proper tyre pressure is vital for safety and durability. Too low pressure compresses the tyre, increasing wear and the risk of blowouts. Too high pressure reduces road grip, causing the trailer to sway. Proper tyre pressure also ensures optimal fuel efficiency.

Tip:
Check tyre pressure on a new trailer after the first 50 km, and then every 2,000 km or once every three months.

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