Tractor tyre pressure – field, road and load

The right inflation pressure is one of the cheapest improvements you can make to a tractor. It affects traction, wheel slip, fuel use, soil compaction, comfort and tyre life. There is no single correct pressure for the whole year: it depends on how much each tyre carries and how fast you drive.

What happens at the wrong pressure?

The aim is the lowest pressure that, according to the manufacturer, carries the load at your speed.

Step 1: work out load per tyre

Load per tyre = axle load ÷ number of tyres on the axle

Axle loads change a lot with implements and ballast. A lifted rear implement can add more than its own weight to the rear axle while unloading the front. See axle load, ballast and implements. Weighing each axle on a weighbridge is best.

Step 2: read the manufacturer's load and pressure table

Each row is a speed, each column an inflation pressure, and each figure the maximum load in kg per tyre. Extract from Michelin's table for Multibib 650/65R42 158D (Michelin Agricultural Tyres Technical Databook 2022, p. 63):

1. Pick the row for your speed.
2. Move right to the first load that is at least your load per tyre.
3. The pressure at the top of that column is the lowest permitted pressure.

Worked example

A tractor has 7,778 kg on the rear axle with a lifted rear implement. The figure comes from the axle load guide, where the implement is an invented example. With two rear tyres that is 3,889 kg per tyre.

• Field work, 10 km/h: 0.8 bar carries 3,885 kg, just too little. 1.0 bar carries 4,315 kg, so the minimum is 1.0 bar.
• Road transport, 40 km/h: 1.0 bar carries only 3,555 kg and 1.2 bar carries 4,000 kg, so the minimum is 1.2 bar.

Field or road?

• If you can change pressure, for example with a central tyre inflation system, use the field pressure in the field and the road pressure on the road.
• If you cannot, always use the pressure for the highest speed you drive, otherwise the tyre is overloaded on the road.
• Lastkalkyl in the app suggests both: the row nearest about 10 km/h for field and about 40 km/h for road.

Front loaders and cyclic loads

With a front loader the front tyres carry very high loads at low speed for short periods. Some manufacturers have special rows for this. BKT, for example, has a row for up to 10 km/h cyclic with front loader, where a footnote requires 0.8 bar extra pressure. Other tables have rows marked Cyclic or CFO, for example for combines. Use them only under the manufacturer's stated conditions.

Dual wheels

With duals the axle load is shared by four tyres, so pressure can often be reduced considerably. Manufacturers sometimes specify a reduced load capacity per tyre in dual fitment, so check the databook. Use the same pressure and the same tyre size inside and outside.

Common mistakes

• The same pressure all year regardless of implement.
• Checking pressure right after driving. Measure cold.
• Using an inaccurate car gauge. At 0.8 bar, 0.1 bar is over 10 %.
• Following the pressure moulded on the sidewall. That is the maximum, not the working pressure.
• Forgetting the front axle. Front and rear almost always need different pressures.

Practical tips

• Keep a note in the cab with pressures for your usual combinations, for example plough, drill and transport.
• Check pressures weekly in season.
• Lower field pressure reduces slip, which often shows up directly in fuel use.

What tyre pressure for ploughing? HT and LT rows

Some manufacturers give two low-speed rows: HT (high torque) and LT (low torque). HT applies to heavy draft work with high torque at the wheels, such as ploughing and heavy cultivation. LT applies to light work. Under HT the tyre carries less load per bar.

Example from Trelleborg's databook for TM900 ProgressiveTraction 710/70R42 173D/170E (p. 19), with 5,000 kg per tyre:

Ploughing with the same load needs 1.2 bar, against 1.0 bar for light work and 1.4 bar on the road. If the table has no HT/LT rows, use the row for your speed.

Comparing brands: 650/65R42

Load per tyre (kg) at 40 km/h from each manufacturer's table:

Standard tyres of the same size are close, but the difference can still decide whether a lower pressure works. The VF tyre carries much more at the same pressure, see IF and VF tyres. Tables are on the tyre pages, for example Michelin Multibib 650/65R42 and Vredestein Traxion 65 650/65R42.

Tyre pressure with a front loader

Front loader work puts short but very high loads on the front axle. Some databooks have special rows for it. Two examples from our data:

• Michelin Xeobib VF 480/60R28: the databook has a row marked Load Fr at 10 km/h where the tyre may carry 3,000 kg at 1.8 bar. The normal 10 km/h row goes up to 2,330 kg at 1.0 bar.
• BKT: a row for up to 10 km/h cyclic with front loader, where a footnote requires 0.8 bar extra pressure.

Conditions vary between manufacturers.

Troubleshooting: signs of wrong pressure

Related questions

What tyre pressure for ploughing?

Use the low-speed high-torque (HT) row if the table has one, with the load per tyre in work. In the example above that was 1.2 bar.

What tyre pressure for road transport?

Use the row for the highest speed you drive, usually 40 or 50 km/h. The pressure is higher than in the field for the same load.

What pressure in tractor front tyres?

Work out the front axle load per tyre and read the front tyre's own table. Front tyres usually carry less and may need a different pressure from the rear.

Should all four tyres have the same pressure?

Usually not. Loads and tyres differ between the axles, but left and right on the same axle should match.

Seasonal tips

• Spring: lower pressure for cultivation and drilling when the soil is moist and vulnerable.
• Harvest: heavy trailers and road work often need higher pressure. Check axle loads with a loaded trailer.
• Autumn: ploughing means high torque; use HT rows where they exist.
• Winter: pressure drops with temperature. Check when tyres are at ambient temperature.

How to do it in the app

In the Pressure guide, pick a tyre and enter load per tyre and speed. The app highlights the lowest pressure in the manufacturer's table that carries the load. We never calculate our own pressures; if there is no table, no pressure is shown. Use Lastkalkyl (load calculator) to start from the tractor weight and implements.

Frequently asked questions

What tyre pressure should a tractor run?

The lowest pressure that, according to the tyre manufacturer's load and pressure table, carries the load per tyre at your speed. It changes with implements and use.

Can I run lower pressure in the field than on the road?

Usually yes. In the example 1.0 bar is enough at 10 km/h, while 40 km/h on the road needs 1.2 bar for the same load.

How do I work out load per tyre?

Divide the axle load by the number of tyres on the axle. With duals there are four tyres on the axle.

Is the pressure on the sidewall the right pressure?

No, it is normally the maximum pressure. The working pressure comes from the manufacturer's table based on load and speed.

What tyre pressure for ploughing?

Use the table's low-speed high-torque (HT) row if there is one. For a Trelleborg TM900 710/70R42 with 5,000 kg per tyre that is 1.2 bar, against 1.0 bar for light work.

What tyre pressure with a front loader?

Some databooks have special front loader rows with their own conditions, for example Michelin's 'Load Fr' row or BKT's footnote requiring +0.8 bar. Follow the manufacturer's instructions.

Last updated 2026-10-15. General information. See disclaimer.