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Self-Repairing Tyres: Will It Be The Future?

Self-Repairing Tyres: Will It Be The Future? | Isn’t it frustrating to pull off a highway just to fix a flat tyre? Thanks to a major breakthrough in science and technology, we have developed a material that makes it possible for tyres to heal and repair on their own quickly. 

This idea of creating self-healing tyre materials is not new though. Back in 2013, Spanish scientists discovered a material that gained  97% of the original tyre stability back within two hours by just letting it rest after cutting it with a sharp blade. 

But what really is it that makes self-repairing tyres the tyres of the future? Well, we have listed some reasons below for you. 

You don’t need vulcanisation for self-repairing tyres.

An important step in the process of manufacturing this tyre of the future is to make sure that it does not need vulcanisation. In 1839, Charles Goodyear added sulfur to the rubber during vulcanisation. That is when the tyre rubber became more durable and turned into the plastic to elastic state but these links can’t be restored when they break so in no way can these tyres be used for the long run. 

To avoid that, scientists have chemically modified rubber to have the same level of elasticity and durability similar to what can be accomplished by vulcanisation. Within a week, a damaged tyre that is made out of this compound can be used again. The healing period is faster when the heat is added to it as it accelerates the healing process. These self-repairing tyres are able to withstand a stress of 754 pounds per square inch. 

There are standards for self-repairing tyres.

In the past, tyre manufacturers did models of tyres that repair themselves when they’re damaged. Supposedly, these models improve road safety as a punctured tyre can lead to a blowout which decreases car handling dramatically, especially during high-speed rides. However, new discoveries have a different approach to self-repairing tyres. Manufacturers of this type of tyre now use a vicious coat under the tread so when the outer layer gets broken, the mass within it can fill in the holes completely. This may already become a permanent solution for car owners so they won’t have to change their tyres even when they are damaged.

What does the future of self-repairing tyres look like? 

Customers can get self-repairing tyres in the near future. While it’s hard to predict which method and technology can be the most reliable, these innovation secures a slot in the future. Self-repairing tyres will allow riders to drive safer and can prevent a lot of road accidents. From now, it’ll only be a matter of time until this technological advancement becomes a standard in all parts of the world. 

If you need new tyres in Brisbane, visit Darra Tyres. If you have any tyre questions, contact Darra Tyres today.

Keeping your family and fleet safe on the road,

Kevin Wood

Top 5 Tips To Keeping Your Tyres In Shape For Your Safety

All car owners should always put routine car maintenance as a priority. Even if most parts of a vehicle is important for it to fully function, one of these parts is vital in terms of safety and functionality: the tyres. Keeping your tyres in shape is critical to the handling, safety and overall quality of your driving. This is why tyres are significant investments and should not be taken for granted. 

You see, driving is one of the most dangerous things we do in our lives and we don’t even realize that. We rely on the four tyres on our vehicles to keep us travelling through our route with safety. And this is exactly why it is extremely essential to keep our tyres well-maintained. 

So how do we do that? Below are the top 5 tips for keeping your tyres in shape for your safety: 

Check Proper Air Pressure.

It is important to keep your tyres aired up to the proper pounds per square inch (PSI). Your tyres are created to work best at a specific PSI. Overinflating them can lead to premature wear and may cause a tyre blowout. Underinflation on the other hand may allow your tyres to come unseated from the wheels during manoeuvres and possibly wears out quicker giving your decreased control over your driving. It is essential for you to keep a tire gauge in your vehicle at all times to help you check the air pressure in your tyres on a regular basis and adjust the air as needed.

Rotate Your Tyres.

The world-famous tyre manufacturer says that rotating your car tyres must be done every 6,000 to 8,000 miles because each tyre wear differently. For front-wheel-drive cars, the front tyres wear twice the rate of the rear tyres. Some tyre experts say that in left-hand-drive areas, the left tyre wears faster than the right tyre so you must keep an eye on that. Having your cars rotated on a regular basis helps in achieving more uniform wear, giving you more consistent performance and a longer tyre service life.

Confirm Your Treads.

For ages now, it is known that tyres should have at least 2/32 inch of tread depth for it to function best and laws agree on this. However, there are new studies which suggest that greater tread depth is a better option for drivers.

Balance Your Tyres.

Getting your tyres balanced from time to time is also very important in maintaining your vehicle. A tyre technician will do this for you using a machine that checks the weight distribution of your ride all allows the placement of lead weights on the tyre rim to achieve a balanced dispersal. Balancing your tyres reduces vibration and gives you a better ride quality.

Align Your Tyres. 

Apart from your air pressure, tread depth and tyre balance – it is also very important to keep your tyres aligned. The front tyres require regular alignment to ensure that there is not too much difference in the way these tyres are pointing. Not having your tyres aligned will cause excessive premature wear. 

Keeping your tyres in shape for your safety is basic but vital. Engaging in a regular tyre inspection and maintenance, plus moderating how you drive can keep you safe on the road and add to the lifespan of your tyres.

If you need new tyres in Brisbane, visit Darra Tyres. If you have any tyre questions, contact Darra Tyres today.

Keeping your family and fleet safe on the road,

Kevin Wood

Buying tyres

Tyre Buying Tips

Get the Best Tyre within Your Budget

So, you need new tyres. The choice is huge and confusing. These tyre buying tips should help you choose the best tyres for your vehicle, driving style and budget.

Match Your New Tyres to Your Car

Tyre manufacturers invest big money into developing new tyres and ensuring tyres are made to keep you safe.

The car manufacturer will have tested many types of tyres on the vehicle. They will have tested for handling, braking, how fast the tyre tread wears, road noise and ride comfort. In your car owner’s manual, it is likely that you’ll find recommendations for your tyres, including size, speed rating and load rating. You should always buy the type of tyre recommended by your car’s manufacturer.

How Do You Know That You Are Buying Tyres to Match Your Car?

When buying new tyres, the markings on the tyre’s sidewall tell you all you need to know. It may look like you need an Enigma machine to decipher the confusing code, but this guide tells you all you need to know:

Vehicle – Tyres are developed for different vehicle types. This is indicated by the following letters:

  • P: passenger car and most 4WD
  • LT: light trucks
  • M: motorcycle
  • T: temporary

Tyre width – The first numbers show the tyre width in millimetres.

Profile – The second number indicates the profile (tyre width to tyre height), usually as a percentage. High-performance tyres are indicated by a low percentage.

Construction – For example, ‘R’ for radial.

Diameter – Indicating which rim size the tyre is designed for, and expressed in inches.

Load Rating – Either expressed as a weight or as an index number.

Speed Rating – The final letter in the code indicates the speed rating. This is the maximum speed the tyre can travel at for 10 minutes without risk of a tyre blowout.

What Tyre Brand Is best?

You will also find the tyre brand and model embossed on the tyre’s sidewall. Premium brand tyres are likely to be more expensive, but savvy drivers buy premium tyres in Brisbane. You find that premium brand tyres could:

  • Save on fuel
  • Give shorter braking distances
  • Offer a more comfortable driving experience
  • Last longer

Whichever brand you choose, we recommend that you fit the same brand on all your tyres, and certainly never mix brands on the same axle.

Why You Should Spend Your Whole Budget on Your New Tyres

The saying that you get what you pay for is certainly true when it comes to tyres. However, never forget the car you drive and your style of driving. Here are some general rules:

  • More affordable tyres are suited to small family cars
  • High-performance cars should be paired with high-performance tyres
  • Always consider your driving style and the surfaces on which you mostly drive
  • Mid-range tyres often provide a good compromise between handling and drive experience and cost
  • Always listen to the advice of a tyre specialist

Are Cheap Tyres Worth the Risk?

If you are tempted to save a few dollars buying cheap tyres, first you should be aware of the risks. Cheaper tyres usually provide less grip on the road. This translates into less ability to avoid a crash.

Cheaper tyres also tend to be made from less stable rubber compounds, meaning you’ll need to replace them sooner. In the long run, buying cheap tyres could be more expensive as well as being less safe.

If you need new tyres in Brisbane, visit Darra Tyres. If you have any tyre questions, contact Darra Tyres today.

Keeping your family and fleet safe on the road,

Dean Wood

Tyre Thread

Tyre Tip #1: Ignore Legal Tyre Tread Depth

Is Your Road Safety Worth 10 Cents Per Day?

For most of us, the car is part of our everyday lives. Just like our mobile phones, social media, eating, drinking and breathing. You top up and recharge your mobile. You check your social media. You make a list and shop for food and drink. And breathing? Well that’s a good habit that you do naturally.

When was the last time you checked your car? Specifically, your tyres? They are the only thing between you and the road. As you are reading this, can you be certain that your tyre tread depth is legal? Or safe?

What Difference Does Your Tyre Tread Depth Really Make?

Tests carried out by Continental Tyres show that braking distances lengthen faster as your tyre’s tread depth reduces. For example, at 85 kmph on a wet road:

  • The stopping ability of a tyre whose tread depth has reduced from 8mm to 3mm is reduced by 16%
  • The stopping ability of a tyre whose tread depth has reduced from 3mm to 1.6mm is reduced by a further 40%
  • A tyre with 1.6mm tread depth will take more than twice the distance to stop as a tyre with 8mm tread depth

Want to know what this really means?

  • With a tread depth of 3mm, it will take you around 2.5 metres further to stop
  • With a tread depth of 1.6mm, it will take you around 8.8 metres further to stop

Why Is the Legal Tread Depth 1.5mm?

Like most tyre manufacturers and other tyre experts, we recommend that you replace your tyres if your tread depth reduces to 3mm. Given the effect on braking distances, it makes sense. If so many recommend changing tyres at 3mm tread depth, the question is, why is the legal minimum only 1.5mm? It doesn’t make much sense.

70 Cents Per Week – The Cost of Changing Tyres 3mm

Continental Tyres didn’t only test braking distances. They assessed the cost of changing tyres at 3mm instead of 1.6mm. They considered average mileage and that tyres should last around 55,000 to 60,000 kilometres.

Continental has calculated that it would cost the average motorist only 70 cents per week to change tyres at a tread depth of 3mm instead of 1.6mm.

70 Cents Per Week for Safer Driving

Your safety on the road doesn’t only depend on braking distance. Deeper tread depth improves your grip on the road. On wet roads, the tread helps to expel water – and that reduces the risk of aquaplaning. On all roads, the extra grip created by extra tread depth provides better handling and safer cornering.

If you ask yourself one question today – as you check your social media after breakfast – it should be this: Is my life worth 10 cents today? You’ve probably got more than that in loose change in your pocket.

Keeping your family and fleet safe on the road,

Dean Wood

Tyre Damage

What Causes Costly Tyre Damage?

Wear and Tear Is Inevitable, But You Can Slow It Down

Most drivers pay little attention to their tyres. If you’re lucky, the first you’ll know that your tyres are damaged is when you are told during a service that you need new tyres. That’s an expense you weren’t expecting. You can delay that expense by understanding what causes tyre damage and how to avoid it.

3 Self-Inflicted Reasons Your Tyre Needs Replacing

Old tyres should be replaced whatever the mileage they have done. This is because over time rubber degrades. Most tyre manufactures recommend that tyres are replaced at least every five or six years. If you are not sure how old your tyres are, read our article ‘How Do You Know How Old Your Tyres Are and If They Need Changing?

Of course, if your tyre tread is worn to the minimum legal tread depth (1.5mm in Queensland), then you must replace your tyres. Usually this is because of wear and tear, and this is usually because of driving style – the first of our three reasons why your tyres need replacing.

Poor Driving Style

If you brake late and hard, drive too fast, and corner at speed, your tyres will become worn faster than they should. If you kerb your tyres when parking, you risk damaging the sidewall with scrapes and bulges.

The type of road you drive on also makes a difference to your tyre wear. Driving on smooth tarmac is less damaging than driving at speed on roads that have potholes, loose gravel and raised manhole covers. Indeed, driving on potholes can cause damage to the internal of your tyre, and to other parts of your vehicle (such as steering, suspension and wheels).


This reason is particularly relevant to drivers here in Brisbane. When it comes to rubber, heat hurts.

The sun’s UV rays damage the structure of tyre rubber. It degrades in the heat. However, this is not the only way that your tyres heat up.

When you are driving, your tyres get hot, though even if you touch the tyre you probably won’t feel how hot your tyres are. This is because the heat is on the inside. By the time you can feel the heat – or smell it – the damage is probably already done.

Speed is the main cause of hot tyres when driving. If your tyres are carrying too heavy a load, this also puts pressure on the tyre and increases the tyre’s internal temperature. Though it is not the heat itself that damages your tyres. As tyres heat up, the air in them expands. It is this increase in tyre pressure that causes the most damage.

The best way to make sure your tyres don’t overheat is to drive slower and with a lighter load.

The Wrong Tyre Pressure

Whether incorrect tyre pressure is caused by overheating tyres or simply inflating to the wrong pressure, the effect on potential tyre damage can be astounding.

Poorly inflated tyres – whether they are underinflated or overinflated – result in tyre damage. Your tyres must work harder, and that makes them heat up faster. It also wears tread away faster. You’ll be using more fuel to turn the tyres and therefore need to change the tyres sooner. That’s a double pick of your pocket.

If your tyre is worn on both edges, you’ve probably underinflated your tyres. If it is worn down the centre of the tyre, it is overinflated. Uneven wear is also a sign of overinflation (or poor wheel alignment).

Good Habits Help Tyres Last Longer

To make your tyres last longer, you should get into good habits as a driver:

  • Check your tyres at least once per week
  • Inflate your tyres to the correct tyre pressure when they are cold
  • Think about tyre load and adapt tyre pressure accordingly
  • Always buy the best tyre you can within your budget
  • Store your tyres out of direct sunlight in a cool, dry place

In Summary

Tyres will degrade over time, but the major reason your tyres become damaged is you! Think about your driving style and the loads you are carrying, and make sure you check your tyres regularly. And always drive on tyres that are inflated correctly.

If you are in Brisbane and have a flat tyre or a tyre that keeps losing tyre pressure, contact Darra Tyres today. Don’t be sorry, be safe.

Keeping your family and fleet safe on the road,

Dean Wood

Tyre Repairs

Are Tyre Repairs Safe?

Which Repair Is Best When You Have a Flat Tyre?

It is most likely that a punctured tyre must be replaced. However, it may be possible to repair the tyre. If your tyre can be repaired, there are three common types of tyre repair that might be used.

Tyre Repair #1: Plugging

A plug is the simplest of tyre repairs and the fastest. When a technician makes this type of tyre repair, they create a plug with a small piece of leather, coat it in rubber adhesive, and plug the puncture with it.

As you drive on the repaired tyre, the heat created vulcanises the rubber adhesive and it hardens to seal the puncture. It is possible to make this type of repair without removing the tyre.

There is a downside, though. The plug must fit exactly, so a strangely shaped hole will be difficult to plug. The plug may work itself loose and the repair becomes ineffective.

Tyre Repair #2: Patching

Patching is an internal repair technique.

A square of rubber is backed with rubber adhesive and glued to the puncture on the inside of the tyre. The adhesive vulcanises as the tyre heats up during driving, and this hardens the repair. Because the tyre must be removed, this repair takes longer and is more expensive than plugging. However, it is also more stable.

Tyre Repair #3: A Plug/Patch Combination

A plug/patch combination is the strongest of the three types of tyre repair. It is sometimes called a mushroom repair and seals the puncture from inside to the outside.

A ‘tail’ is added to the rubber patch and threaded through the puncture hole to act as the plug. The tyre must be removed to make the repair, and while this type of repair is the most effective it is also the most complex. It takes longer than either of the other two types of repair and is the most expensive.

How Is a Combination Plug/Patch Tyre Repair Made?

Making a combination plug/patch tyre repair is a complicated process. It’s not like making a repair on a bicycle tyre! There are many steps involved:

  1. Remove the tyre and inspect

The tyre must be inspected thoroughly to make sure that it can be repaired.

  1. Mark up the damage

The damage is located and marked, and foreign objects are removed.

  1. Drill from the inside

The puncture hole is drilled from the inside to make it uniform.

  1. Drill from the outside

The puncture is drilled from the outside until no resistance is felt.

  1. Clean the area of damage

The area of damage is thoroughly cleaned to around 1cm to 2cm larger than the size of the repair patch using pre-buff cleaners and a repair scraper.

  1. Mark and clean internally

The repair patch is held on the inside of the tyre where it will be fixed, and the tyre is marked up around the patch. The area marked is buffed to around ½cm larger than the repair patch using a domed buffing rasp. It is essential that the area is flat.

  1. All dust is removed

All dust is removed, and the repair area is cleared of wire and fluffed cords.

  1. Vulcanising accelerator is added

A vulcanising accelerator is added to the puncture channel and the buffed patch area.

  1. Plug the puncture

The patch’s tail is threaded through the puncture hole.

  1. Pull the tail through

The tail is pulled from outside the tyre so that the patch sits tight and flush internally.

  1. Flatten the patch

The patch is rolled from its centre to its edges using a corrugated tyre stitcher. This removes air bubbles and ensures complete contact with the buffed interior of the tyre.

  1. Seal internally

The repair patch and plug base are sealed with an inner liner sealant.

  1. Remount

The tyre is remounted onto the wheel and inflated to its correct pressure.

  1. Finish off

To finish the repair, the plug is cut flush with the tread of the tyre.

Should You Repair a Tyre?

As you can see, there are three ways in which a tyre might be repaired. If you have a flat tyre, you must take it to a tyre shop to be inspected. The tyre specialist will tell you whether it can be repaired after first assessing the damage to the tyre. If a repair is made, you should remember that a repaired tyre is never as strong as a new or undamaged tyre.

If you are in Brisbane and have a flat tyre or a tyre that keeps losing tyre pressure, contact Darra Tyres today. Don’t be sorry, be safe.

Keeping your family and fleet safe on the road,

Dean Wood

Checking Tyres

Is Now the Time to Check Your Tyres?

What Is at Stake if Your Tyres Remain Unchecked?

A tyre check is easy to do. It takes no more than five minutes and ensures that your tyres are running at the right tyre pressure, that your tyre tread depth is legal, and that there is no damage that could make it unsafe to drive. Yet a tyre check is the most neglected of all vehicle maintenance routines.

Neglect to Check Your Tyres and You Ignore Your Safety

New tyres have around 8mm or more of tread depth. While the legal limit is a minimum of 1.5mm tread depth, we recommend that you don’t go below 3mm.

If you let your tread depth reduce to 1.5mm, braking distance can be as much as 50% more in wet weather than it would be with a tread depth of 3mm. That could be the difference between life and death – of you, your passengers, other road users and pedestrians.

It’s not only tread depth that compromises safety on the roads when you are driving. Bulges grazes, cuts and embedded items all affect the quality of a tyre. A damaged tyre is more likely to leak air, and it is more likely to suffer a tyre blowout – at high speed, a tyre blowout could be fatal.

Do you know what condition the tyres you are driving on are in? When was the last time you checked your tyre pressure? When did you last check your tyres for bulges on the inside and outside sidewalls?

Now Is the Time to Check Your Tyres

The condition of your tyres could change after only a few miles of driving. Embedded glass could put you in danger on your next trip. Yet most drivers never check their tyres, until they feel that their ride is a little bumpier than it used to be, or that the handling is not as sharp as it once was.

By this time, it may be too late. The chances are you’ll still put off that simple, five-minute check because you have ‘more urgent things to do’.

After a while, you become used to the longer braking distances and the worsening handling round corners. Until that one time your mind is elsewhere, and you drive the car like you used to when your tyres were in good condition. Like you should always be able to.

Then you lose your grip on a bend. You drive a little too fast, and brake a little too late. The only question to answer now is, will the blood on the road be yours or someone else’s?

If there is a golden rule you should remember it is this: now is always the time to check your tyres.

Let a Professional Check Your Tyres

While a tyre check is simple, the basic five-minute check may still miss technical problems with your tyres. Internal damage or degradation, for example. That’s why you should also consider a regular tyre check made by a professional. Specialists know all the danger signs, and they will recommend action that you can take to help your tyres last longer – such as tyre rotation, for example.

What if You Need New Tyres?

If you check your tyres and find that one or more have shallow tread or damage, don’t risk your life by continuing to drive on it. Replace that damaged tyre immediately.

You might be tempted to buy part-worn tyres to save money. But part-worn tyres are a dangerous, false economy because they are:

  • Older, and may be degraded by age
  • Will have suffered wear and tear, with damage to sidewalls or internally
  • Have shallow and inconsistent tread depths, affecting grip, handling and braking distance

Premium tyres are the best option. They could save you money on fuel, benefit from shorter braking distances, offer a safer, quieter drive, and last longer.

However, not all drivers have deep enough pockets to buy premium tyres. Which is why we also stock good-quality, affordable tyres.

If you have checked your tyres and found they need replacing, do so. Don’t leave it. You are only risking the safety of everyone on the road, and everyone in your vehicle. And when you do replace your tyres, you should always invest in the best tyres in your budget.

Please check your tyres now. If you don’t, you are taking a risk with everyone’s safety when you drive. One death on the road is one death too many. If you are in any doubt about the condition of your tyres and live in Brisbane, contact Darra Tyres. We’ll discuss your needs, consider your vehicle and driving style, and make sure you invest in the best tyres in your price range.

Keeping your family and fleet safe on the road,

Dean Wood

High Performance Tyres

Should I Buy High-Performance Tyres?

Is the Expense Value for Money?

High-performance tyres are made from softer rubber compounds than other tyres. They have been designed to provide extra ride comfort and greater handling capability at higher speeds. They benefit from innovative treads that are designed to increase grip on the road and when cornering.

Are High-Performance Tyres Right for You?

When you need to change tyres, you should buy tyres that match your driving style, your vehicle, and the roads or other surfaces on which you drive. You might be tempted to opt for high-performance tyres – especially if you do a lot of highway driving at speed.

If you watch Formula 1, you will have seen how high-performance tyres give extra grip. The softer compound makes the car stick to the track. The driver gets round the track negotiating bends and corners at high speed. However, during a race lasting a couple of hours or less they may get through two or three sets of tyres.

If you buy high-performance tyres, they will last much longer than those used in Formula 1. You won’t be melting rubber at such high speeds, and the rubber compound used on commercial high-performance tyres is not nearly as soft as that used on Formula 1 tyres.

If you want better handling, more grip and improved braking power, then high-performance tyres might be right for you. Before you make this decision, though, read the rest of this article.

What Vehicle Do You Drive?

As you might expect, if you drive a high-performance car you’ll probably benefit more from high-performance tyres. However, performance tyres are becoming more popular among drivers of other car types because of the advantages they offer – manufacturers are now producing performance tyres for smaller cars.

The Disadvantages of High-Performance Tyres

Before you rush to buy high-performance tyres, it pays to be armed with all the facts. While you will benefit from the improved grip, better handling and shorter breaking distances, there are some disadvantages, too. These include:

  • Performance tyres are more expensive

Like all tyres, the bigger the tyre you need the higher the price you’ll pay. You’ll also pay a premium for how high-performance the tyre is. A small high-performance tyre might cost around $130. A high-performance tyre that you could use on a racetrack might set you back as much as $2,000.

Generally, you should expect to pay around $230 for a high-performance tyre for a 15-inch wheel.

  • You’ll use more fuel

Better handling and greater grip come at a price on top of the tyre’s cost. That price is lower fuel economy. Your vehicle must work harder to combat the traction on the road, and that means using more fuel.

  • Shorter tyre life

The softer rubber compound wears quicker, and this means your high-performance tyres won’t last as long other tyre options. You’ll be paying more for a set of new tyres sooner.

Summing Up

High-performance tyres should help you stay safer on the road. You’ll benefit from better handling and surer braking. However, your initial outlay will be greater and there is a compromise between grip and fuel consumption. You are also likely to need to change your tyres sooner.

Before making your decision, contact Darra Tyres in Brisbane. We’ll discuss your needs, consider your vehicle and driving style, and make sure you invest in the best tyres in your price range.

Keeping your family and fleet safe on the road,

Dean Wood

Heavy Vehicle Tyres

The 14 Reasons Why Your Heavy Vehicle Tyre Is Dangerous

Ensure Your Vehicle Is Safe and Legal on Australia’s Roads

The tyre inspection is one of the most important jobs that a driver, operator or inspector does. If your heavy vehicle’s tyres are below the required standard, you are putting yourself and other road users at risk. How do you know what the tyre standards are for heavy vehicles? Do your drivers know the 14 reasons to reject a tyre?

National Standards for Heavy Vehicle Tyres

Since February 2014, the National Heavy Vehicle Regulator (NHVR) has been Australia’s independent regulator for all vehicles over 4.5 tonnes gross vehicle mass (GVM). Its job is to ensure that heavy vehicles are safe and efficient on Australia’s road network. The regulations that it oversees include the standards laid out in the National Heavy Vehicle Inspection Manual (NHVIM). It is in here that you will find the standards for heavy vehicle tyre checks.

Do Your Inspectors and Drivers Know the Heavy Vehicle Tyre Standards?

The NHVIM has been composed to provide a consistent approach to heavy vehicle standards across Australia. Its aim is to ensure compliance with standards, to improve safety, and to reduce vehicle downtime.

It wasn’t written by people with no experience, either. The regulator consulted with the industry and developed the NHVIM to provide inspectors and operators with standards that actually achieve what they set out to achieve.

For fleet managers, the NHVIM provides the criteria for heavy vehicle inspections. This includes all the reasons a heavy vehicle tyre should be rejected when inspected.

Here are all 14 of these reasons to reject a heavy vehicle tyre, with explanations where needed.

1.    Insufficient Tread

The law states that a tyre must have a minimum of 1.5mm of tread in a continuous band around the whole tyre. This tread depth must extend at least 75% of the width of the tyre.

Most tyres have tread wear indicators built into them, though these aren’t included when assessing a tyre’s tread depth around its circumference.

Good operators will replace heavy vehicle tyres sometime before they reach legal minimum tread depth.

2.    Tyres Don’t Match the Tyre Placard

Most vehicles have a tyre placard fitted to the door jamb. This shows the dimensions and air pressure levels that must be maintained. If there is no tyre placard, these details will be in the owner’s manual. A tyre that does not match these standards should be rejected.

3.    Tyre Damage

Deep cuts, bumps, bulges, exposed cords, chunking, and other signs of carcass failure.

4.    Regrooved Tyres

Only if it is stipulated on the sidewall of the tyre that it can be regrooved is regrooving permitted.

5.    Wider Than Mudguards

If the heavy vehicle tyre’s sidewall projects beyond the width of the mudguard when in the straight-ahead position.

6.    Non-Approved Modifications

If the tyre has been fitted with a non-OEM front wheel (i.e. rim and tyre) that has not been approved as a modification.

7.    Not Constructed for Unrestricted Road Use

8.    Illegal Retreads and Remoulds

Only tyres that are marked with ‘Retread’ or ‘Remould’ are capable of being retreaded or remoulded. The tyre should also be marked with its maximum speed (e.g. Speed Limited to 125 km/h).

9.    Illegal Speed Rating

The speed rating of all tyres must be no less than 100km/h or the vehicle’s top speed, whichever is the smaller. The exception to this is if the manufacturer has specified a lower speed rating.

10. Manufacturer’s Tyre Load Ratings Are Less Than the Vehicle’s Ratings

Any tyre fitted to a vehicle with a GVM of more than 4.5 tonnes is not suitable for road use if the tyre load ratings are less than the minimum ratings specified originally by the vehicle manufacturer.

11. Tyres Are in Contact

If dual tyres are fitted, there must be space between them. If they are touching, they must be removed and replaced.

12. A Tyre That Is in Contact with the Vehicle

If the tyre is in contact with any part of the vehicle – the body, chassis, braking, steering, frame, suspension – at any point of travel must be rejected.

13. A Tyre That Could Damage Roads

If cleats or other gripping devices could damage the road on which the vehicle is travelling.

14. Incompatible Tyres

A tyre that is not compatible to the rim to which it is fitted.

In Summary

When your drivers or maintenance staff check the tyres on heavy vehicles, it is essential that they check for all 14 reasons to reject a tyre. If you asked your drivers to write the list of 14 heavy vehicle tyre rejections now, do you think they could do so?

A simple tyre test will help your fleet’s vehicles to be safe and legal on Australia’s roads. When these tests show up heavy vehicle tyre frailties, contact Darra Tyres in Brisbane for the professional assistance you need.

Keeping your family and fleet safe on the road,

Dean Wood

Cheap tyres

How Can Fleets Get the Best Performance from Cheap Tyres?

Tyre Maintenance Tips a Fleet Manager Cannot Afford to Ignore

We always recommend that fleet managers buy the best-quality tyres their budgets allow. The cost is front-loaded. The benefits become apparent over time. Quality tyres last longer than cheap tyres. They are made with better components, and their design and manufacture benefit from years of expensive research and development. They are produced to keep your drivers safe on the road.

But what if your budget is tighter today? What if you must buy cheap tyres for your fleet?

In this article, I discuss how you can get the best from cheaper tyres.

Air Pressure Is Key to Cheap Tyre Performance

Your fleet’s tyres do a specific job. They carry loads on the road. Whether cheap tyres or a premium brand, if your tyres are not inflated correctly, they won’t be as effective.

Drivers should check tyre air pressures every day when the tyre is cold – before they load up and leave. The driver should know the load they will be transporting and inflate the tyre according to the load and tyre pressure recommendations.

If the inflation level is wrong, the tyre will wear faster. Remember, too, that the quality of air in the tyre makes a big difference to a tyre’s performance.

What Quality of Air Do You Pump into Your Tyres?

Especially for tyres carrying heavy loads, the quality of air pumped into them is crucial. And before you ask, no, air isn’t air! Just like instant coffee granules are not coffee beans, and not all engine oils are the same.

Air compressors deliver air that is riddled with moisture, particulates, and oil mist from the air coming into it. A pressure swing adsorption (PSA) unit extracts nitrogen from this, ensuring that dry, clean gas is pumped into the tyre. If normal compressed air is added to the tyre, all the benefits of the cleaned air are lost.

The best way to think about this is to consider the oil that you put into your fleet vehicles. If that oil were full of impurities and particles, it wouldn’t take long for the engine to start degrading. The same is true of tyres. Put poor air in, and you’ll find they degrade faster. For example:

  • Oils (hydrocarbons) attack the rubber on the inside of the tyre
  • When this happens, air escapes through the tyre
  • The affected tyre requires more regular inflation

Moisture in the tyre has a different effect. It causes the tyre to expand. This is because moisture turns into vapour when heated, thus inflating the tyre when it is in motion. It is not unusual for tyre air pressures to increase from around 140 PSI when cold to more than 180 PSI when operating at speed. High moisture content in the air inside the tyre will cause the tyre to expand. This reduces handling ability and causes extra wear along the centre of the tyre.

The answer is to ensure that only high-quality air is used in cheap tyres. This will help the tyre to last longer and perform more effectively.


Whether you invest in premium brand tyres or are restricted to buying cheap tyres, how your tyres are maintained is a major determinant of your fleet’s tyre costs – which could be around 3% of your fleet’s total costs. Drivers should ensure that tyres are checked before leaving your depot. They should test for air pressure, and for cuts, grazes and bumps, and ensure that tyre tread is within legal limits.

Using quality air will help cheaper tyres last longer. Of course, using quality air in the highest-quality tyres is the very best solution.

For all your fleet’s tyre needs in Brisbane, contact Darra Tyres today. We’ll help you cut tyre costs while maintaining efficiency and safety.

Want to know more? Do you need your tyres checked in Brisbane? Feel free to contact us to book an appointment.

Keeping your family and fleet safe on the road,

Dean Wood

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