The perils of over or underinflating agricultural tyres

How to work with the optimum footprint in all conditions

Agricultural tyre pressure is one of the most important factors in getting the best from your tractor and other farming vehicles. Many operators run their agricultural tyres with the wrong inflation. In this blog post, I’ll examine the consequences of getting the air pressure wrong on your agricultural tyres, and how to ensure you run your tyres at the optimum footprint.

Be prepared for expensive field work with the wrong tyre pressure

Your tyres are hugely important in the field. The wrong tyre pressure will affect vehicle performance. Soil will be compacted and crop production affected. And poorly inflated tyres wear faster and damage more easily. Many operators ballast their tyres in attempts to increase performance.

Manufacturers’ studies have shown that incorrect tyre inflation can mean as much as a 40% loss of engine power. It is caused by slipping and poor rolling resistance. Add this to power loss from the transmission and additional equipment, and you’re looking at up to a 50% reduction in power. This amount of power loss puts an incredible strain on a tractor’s engine. It must work harder and uses more fuel. Repair and maintenance issues will increase. All this adds up to a big hit on your pocket.

Functionality depends on footprint

Increased traction depends upon its footprint – the amount of tyre surface area in contact with the ground. The greater the footprint, the greater the traction. So, you would think that running agricultural tyres at the lowest possible inflation would increase efficiency because a larger footprint gives less wheel slipping, and results in longer tyre life and less soil compaction. Wins all round. But it’s not quite this easy.

Agricultural tyres must also carry loads without causing damage to their construction. When this happens, all bets are off. Damage to tyres increases, power is harmed, and costs increased. So, it’s imperative that you run your tyres at the optimum pressure for optimum results.

Agricultural tyre footprint – a constantly changing factor

The optimum tyre footprint doesn’t simply depend on tyre pressure. It also depends upon the load being supported and the tyre size, and ground being driven on. The optimum footprint will constantly change, as the load being carried changes. So, you need to reach a happy medium.

How you do this is to stick within the tyre manufacturer’s guidelines – the tables they produce on tyre sizes, maximum loads, tyre pressures, and speeds. Operate a tyre at 10% below its stated optimum pressure, and you’ll decrease its life by 15%.

The perils of overinflation of agricultural tyres

It’s not only underinflation that can affect tyre life and performance in the field. Over-inflation will increase the likelihood of tyre damage and more. For a start, driving on overinflated tyres will hit your driver hard. Every bump reverberates up the spine. Comfort reduces, and performance isn’t far behind. It is indicative of what over inflation does to tractor performance – wear and tear on tyre and vehicle increases. You’ll use more fuel, increase soil compaction, and reduce tyre life.

What’s worse – overinflation or underinflation?

There isn’t much difference between the effects of overinflation and underinflation. A 20% overinflated tyre causes 30% loss in performance, while a 20% underinflated tyre will cost you 26% of your performance.

However, if you drive your tractor on the road with underinflated tyres, the lugs will start to wear faster. Your rear lugs will be more severely damaged. It could cause bead slip – and leads to rapid destruction of the tyre.

Check your tyre pressure regularly

Neglecting your tyre pressures on your agricultural vehicles will impact your bottom line.

An underinflated tyre will increase fuel consumption, lead to sidewall damage, uneven wear and bead slip, which eventually destroys the tyre.

An overinflated tyre will increase fuel consumption, increase wear on the vehicle and tyre, increase soil compaction, and result in reduced tyre life.

When it comes to your tyres, check tyre pressures regularly. Keep them within the manufacturer’s guidelines for load, size and speed. One final tip: make sure your tyres have a valve cap. It keeps dust and dirt out of your tyre, but, equally as important, it prevents the natural air loss through tyre valves.

For all your agricultural and other tyre needs here in Brisbane, contact Darra Tyres today.

Keeping your family and fleet safely on the road,

Kevin Wood

About the Author

Kevin has been at the forefront of the tyre industry for over 20 years. Kevin's speciality is in industrial and commercial tyres including the management and upkeep of fleets. Kevin has worked with vehicles his whole career from painting, mechanical, suspension and panel beating he has also spent time in the Australia Army as a driver. He has driven all size of vehicles throughout his career so understands the demands placed on drivers.