Tag Archives for " tractor tyres "

Question about tyres

10 questions that Queensland drivers frequently ask about their tyres

All you need to know about your tyres – or is it?

We get asked many questions about tyres. These are the 10 most common, with the answers you need.

1.    My tyre placard mentions particular tyres and rims. Can I fit different to this?

Yes, you can; but the tyre/rim combination and width/diameter must meet certain requirements. The amount that the width and diameter may change by depends upon the type of vehicle. There are different rules for 4WDs, passenger vehicles, etc. You can learn more by reading the Minor Modifications publication (PDF, 414 KB).

2.    Can I increase my vehicle’s ride height?

There are various ways that you could increase the ride height of your vehicle. These include by increasing your vehicle’s tyre dimension, lifting its suspension, or by using body blocks. The amount you can raise it depends on which methods or combination of methods you use to do so. The most that you can raise your ride height by for each single method is:

  • 50mm by increasing the tyre dimension
  • 75mm if raising by lifting the suspension
  • 50mm by using body blocks

However, if you are using a combination of these methods, the most your vehicle can be raised is 150mm.

Just to complicate things a little more, these limits are not applicable to all vehicles. They are a good guideline, but for the exact raise you can make to your vehicle you should examine the National Code of Practice for Light Vehicle Construction and Modification (PDF, 1.93 MB).

3.    Can I use low-profile tyres with a wider diameter on my vehicle?

This is possible to do, but you must make sure that the overall diameter, load rating and speed rating comply with legal requirements. Often, low-profile tyres will be fitted to larger diameter rims; this maintains the overall diameter to requirements. Once more, you should refer to the National Code of Practice for Light Vehicle Construction and Modification (PDF, 1.93 MB).

4.    What is the maximum tyre diameter increases and decreases I can make to my 4WD?

With some 4WD vehicles, you may increase tyre diameter by up to 50mm and decrease it by up to 26mm, from the vehicle manufacturer’s recommended diameter. These are:

  • 4WD passenger vehicles specifically designed for off-road use
  • 4WD goods vehicles and their 2WD equivalents, if the chassis and running gear are essentially the same as the 4WD versions

However, all-wheel drive vehicles (AWDs) are not included in these. The Minor Modifications publication (PDF, 414 KB) provides the information you need.

5.    Can I lower the speed rating of my tyres?

You may want to lower the speed rating of your tyres, and this is possible, providing the tyres meet certain minimums. These are:

  • 140km/h for off-road passenger vehicles
  • 180km/h for other cars or car derivatives carrying up to nine adult passengers in seated positions
  • 120 km/h for other motor vehicles

There is an exception to all these rules: if your vehicle has a lower top speed than the above, then the tyre may not have a speed rating above the vehicle’s top speed.

6.    Can I fit different brand tyres to the same axle?

Yes, though it is preferable to fit the same brand. However, what you cannot do is fit tyres with different construction (e.g. cross-ply, steel radials, textile radials, etc.).

We also recommend that tread patterns should be the same on tyres fitted on the same axle, though there is no legal requirement to do so.

7.    How often should I change my tyres?

Tyres last far longer today than they used to. However, when they need changing depends on many factors, such as:

  • The type of road surface on which they are driven
  • The wear and tear suffered
  • The kilometres covered by the tyre
  • Irrespective of any of the above, the age of the tyre

Most tyres will last between 60,000 and 80,000 kilometres. However, manufacturers recommend that tyres should be changed every five years at a minimum, due to age degradation of the rubber.

8.    How often should I check my tyres?

We recommend that you carry out four tyre safety checks at least once per month, and more often if you drive every day. If you are making a long journey, you should also carry these checks out. These four essential checks are:

  • Tyre pressure
  • Condition of the tyre wall
  • Tread depth
  • All the above on the spare

9.    Should I change all four tyres are the same time?

If you rotate your tyres, the wear and tear on them should be equal. If this is the case, you will probably need to change all four tyres at the same time. However, if not all four tyres need to be changed it is always best to change the tyres on the same axle simultaneously. This will ensure that handling and grip is uniform on the same axle, which will improve your safety on the road.

10. What is the danger of driving on worn tyres?

If you drive on worn tyres, you could be given a hefty fine. However, this should not be your main concern. Worn tyres provide less grip and traction. Your handling will be worse, and your braking distances will be longer. Worn tyres are a big contributor to road accidents and fatalities in Australia.

Do you have a question about your tyres? Are you unsure whether they are legal or if they should be changed? For the answers to all your tyre questions, contact Darra Tyres.

Keeping your family and fleet safe on the road,

Kevin Wood


What is the right tyre for tractor users in Queensland?

Advice to help your tractor work harder and reduce costs

When you need new tyres for your tractor, there are plenty of options. This makes choosing your tyres more difficult. Here at Darra Tyres, it’s our job to make this choice easier. In this article, you’ll learn about the tyre options available for agricultural vehicles, and how they differ for all your agricultural needs. Knowing which type of tyre is needed should help to save you time and money and make your work more efficient.

Types of tractor tyres

There are three types of tyres for tractors. Each has different specifications, and each is manufactured for a different use.

Turf tyres

These are designed to be driven on grass and fields, particularly for mowing and landscaping jobs. They are ideal for work required on sports grounds and golf courses, as the tread patterns are less aggressive than other types.

Construction tyres

These are mostly used on hard surfaces such as concrete, gravel, and tarmac, and so are designed to resist wear and tear. The load is spread across the tyre with wider treads, creating a larger contact area with the ground.

Agricultural Tyres

This is the most common of tractor tyres, for use in fields and especially on soft soils. The large tread creates excellent traction, giving better grip and aiding work in wet conditions.

Bias-ply or radial tractor tyres: which is best?

Having identified the type of tyre you need for the work it will perform, the next choice to make is the tread type. The way the tyre is constructed, either bias-ply or radial, affects the tyre’s performance.

Bias-ply tyres

Bias-ply tyres are constructed by laying successive plies at opposing angles – most commonly, these are laid at angles of 30 to 40 degrees – creating a criss-cross pattern. This means the tyre can flex more easily. This cushions the ride, making for a smoother driving experience. However, bias-ply tyres also suffer from increased rolling resistance and lower traction, increasing fuel consumption and decreasing working efficiency.

Radial tyres

The plies on radial tyres are laid at an angle of about 15 degrees to the tread and run in the direction of the tyre. This helps to stabilise the tyre on a rough and uneven terrain. Though more expensive to buy than bias-ply tractor tyres, radial tyres are the most popular because they:

  • Provide better traction
  • Offer less wheel slippage and better handling
  • Reduce rolling resistance and fuel consumption
  • Are more resistant to cuts, tears, and punctures
  • Enable more ground to be covered in less time

Radial agricultural tyres tend to last longer than bias-ply. Your operations should benefit from greater efficiency, lower fuel consumption, and less regular tyre changes. Over the longer term, choosing radial tyres for your tractor, and making sure they are the right type for the work they will be doing, could save you a lot of money.

For your next set of tractor tyres, contact us today. We’ll help you make the right choice to reduce your costs and increase your efficiency.

Keeping your family and fleet safe,

Kevin Wood

If Ferrari made tractors, who would make the industrial tyres?

Tractor tyre innovation explained

When you think of tractors, you won’t associate them with Ferrari. However, this could change in the next few years. It was about this time last year that Zetor exhibited its Pininfarina-designed concept tractor, a tractor designed for the future. Sleek, modern, and Ferrari red. Not made by Ferrari, but created by the same design house that is behind some of the most iconic Ferraris of all time.

Here I look at the design, and if it is likely to usher in a new age of tractors in Australia.

What was Zetor thinking?

Zetor is a brand name that most non-agricultural people will never have heard. It’s a company that has sold more than a million units in 100 countries. It clearly knows its tractors. Its main manufacturing plant is in the Czech Republic, and its history of success is based upon engineering quality, design, and innovation.

A collaboration with Ferrari designer Pininfarina must be considered to be at the forefront of tractor design innovation. The result was a concept tractor, unveiled at last year’s Agritechnica fair in Hannover, Germany.

When you examine the Pininfarina-designed tractor, it’s easy to imagine the vehicle with a 0 to 60 mph rating on it. That wasn’t the case, but its aerodynamic lines are groundbreaking.

The tractor wasn’t built simply to look good, however. It had to be robust, reliable, and simple to work on. It was also designed to increase brand awareness. The red colour was a given – that’s something that Ferrari and Zetor already had in common. Something else that was evident in the concept model was functionality  (a constant from Zetor tractors) and grace  (a constant in Ferrari cars).

What tractor tyres would a Zetor concept use?

To deliver on its promise, the Zetor concept tractor would need to match its design, grace and functionality with tractor tyres that offer the same qualities. Could this be possible when it comes to tractor tyres?

Maybe. Last year Michelin unveiled a concept tractor tyre tread that could become an industry standard.

How do tractor tyre manufacturers improve performance?

When designing new tractor tyres and tread patterns, manufacturers put their concept tractor tyres through a whole range of tests. Sometimes they develop new tests to validate new findings. Once they’ve produced what they believe is an improved tractor tyre, they test it for functionality and robustness in the field. They have working farms to test the tyres, provide feedback, and then retest after refinements have been made. It could be months or even years before you see a tyre move from concept to production.

When it designed its new concept tractor tyre, Michelin considered soil compaction, ruts and depth of ruts, fuel savings, and length of service.

Soil compaction

Michelin uses a sand track to make systematic comparisons between tyres. It is something that is tough (if not impossible) to do in the field: different soil conditions, weather and humidity make it so. What happens on sand will happen on soil, and to ensure that results are consistent the tractor trye tests are repeated several times.

The improvements that the tractor tyre manufacturers want to see are larger footprints and shallower ruts.

How is the soil rutting test done?

The research boffins dig a ditch (okay, so they have the ditch dug for them) and fill it with soil of different colours. A tractor equipped with the new tyres then drives over the ditch. The impact is measured and analysed by digging out perpendicular to the line of the test drive.

Measuring soil compaction

The researchers use a test called a ‘penetronometer test’ which is used in the field to gauge the impact of soil compaction. Measurements are taken at regular intervals with a penetrometer – this measures how compacted the soil becomes, with more compacted soils leading to stunted crop growth.

Fuel consumption testing

The fuel test is used with maximum tractor output, in a soil preparation situation. The tractor has a tooth plough attached and covers a set distance. Tyre spin is measured, and sometimes an effort sensor is used to measure the traction force for better fuel consumption estimation.

Industrial tyres life

Tractor tyre life is measured by what is known as an ‘accelerated wear test’. It’s rigged to roll in realistic conditions for 24 hours a day. The test is done driverless to negate the effects of driving style. After a pre-set period, the tractor tyre tread is measured. These tests are then consolidated with actual farm use data to give an accurate assessment of tyre life.

What are the latest Michelin tractor tyre innovations?

Using these tests among others, Michelin is constantly innovating their tractor tyres. In fact, the company spends in the region of $450 million every year on tyre research and development.

Michelin’s Ultraflex Technology allows you to run tyres at lower inflated pressures. It increases footprint and reduces soil compaction. You’ll find your fuel consumption falls, the tyres last longer, and your crops grow better.

Just like Zetor developed a concept tractor, Michelin developed a concept tyre based on the Ultraflex Technology. When the concept tyre was first developed, Michelin’s Northern European Commercial Director, Mike Lawton, said:

“Farmers of the future face the substantial challenge of feeding ever-increasing populations with less arable land available to them. As a result, tractor tyre and machinery choice is going to become ever more important to maximise yield. Lawton continues… “Michelin researchers are exploring all avenues to develop the tyres of the future; this latest concept is evidence of this work in practice.”

Zetor’s concept tractor may be some years from coming on to full production, but Michelin’s latest tractor tyres are available now. Contact the team on 3375 3566, and we’ll be glad to discuss all the tyres we stock and our various tyre service options.

Keeping your family and fleet safely on the road (and fields!),

Kevin Wood