With fleets busy out on the road in 2017 let’s inspect the most critical functioning part that’s so easy to neglect.
AFMA spoke to Bridgestone Australia’s national technical field service manager, Jon Tamblyn about the most vital feature on every fleet vehicle in the country. Tyres might not be the most exciting aspect of your fleet, but they’re the single most important safety feature on the whole vehicle because ignoring tyres means you’re out of touch.
Here’s some expert advice, but first let’s get to know a bit about Jon.
What was your first or most memorable experience with tyres?
I’ve been a car enthusiast since I was young, so I always knew what a huge difference tyres could make to your car. The first car I ever bought was a Datsun 260Z that needed a bit of work but, being a university student at the time, I couldn’t afford to fix everything at once. I decided to replace the suspension bushes and purchased some quality tyres, which made an unbelievable difference and completely transformed the vehicle.
What do you enjoy about working in the tyre industry? Where does your enthusiasm for the job come from?
It’s nice to now be working in a part of the motoring industry where I can help make a difference to other people’s cars.
I like that there are so many different aspects to a tyre. We could make a tyre that grips and handles amazingly but, if its wear life was terrible, all that performance would be for nothing. Being able to push the envelope, and strive for perfection across the board, keeps things interesting for me as an engineer.
As fleets roll out for 2017, why do tyres need checking for optimum pressures and how do tyres deflate? What are the effects of underinflated tyres?
The air in tyres supports the vehicle’s load. When tyres are underinflated, they flex a lot more and could potentially fail if they’re run at a low pressure for long enough. Their contact with road is also going to be poor, giving the driver less grip and taking longer to come to a stop. On the other hand, if you overinflate the tyres, they will lack the flexibility needed to conform to irregularities on the road surface – again resulting in less grip and reduced ride comfort.
All tyres naturally lose air pressure. Even a tyre in perfect condition will lose around one or two psi per month as the pressurised air inside diffuses through the rubber itself. That’s why you should check your tyre pressures about once a month.
No matter how fast or slow you’re going, underinflated tyres perform much worse than tyres that are correctly inflated. Tyre pressure is always important, whether you’re driving in the city at urban speeds or the country at high speeds.
Your tyre pressures should match what’s specified on your vehicle’s tyre placard to achieve optimum performance. You’ve only got one handprint of tread connecting each tyre to the road, so you need to maximise the way that handprint is going to work for you by having your tyres inflated to the right pressures.
How is safety of the average sedan/hatch fleet vehicle compromised by underinflated tyres in emergency driving 
scenarios (swerving, hard braking, wet conditions)?
Any vehicle with underinflated tyres will experience vastly reduced grip and steering response. The tyres will respond much more slowly to the driver turning the wheel or putting their foot on the brake. Essentially, it could mean the difference between having an accident and avoiding one.
What does ‘tyre life’ actually mean, in terms of balding, cracking and hardening, and how do these conditions take effect on the road?
A tyre is legally worn out when it reaches the wear indicators located in the tyre’s main grooves at 1.5mm. However, tyre performance does begin to suffer before that time. For example, as the grooves become shallower, the tyre’s wet grip lessens substantially as there’s less space in the grooves to evacuate the water.
As you might imagine, rubber properties are critical to tyre performance. They change over time as they react with different variables, including sunlight, the ozone in the atmosphere, hot bitumen etcetera. As the rubber properties change, the tyre’s performance lessens. Quality tyre manufacturers spend millions of dollars optimising rubber properties to maximise their longevity – another reason why it’s important to invest in quality rubber for your car.
In addition to regular inspections and pressure checks, Bridgestone recommends you have your tyres checked by a tyre professional every year after five years of use. If they’re still on your vehicle after 10 years, we recommend they are replaced regardless of visual condition.
Why is nitrogen used for extreme military and motorsport purposes and not mainstream cars, bikes and light 
commercial vehicles? Are there any tangible, cost-saving benefits to paying for nitrogen to inflate fleet vehicle tyres given air is about 80% nitrogen anyway? How much additional life can be expected by switching?
Many retail tyre outlets, including Bridgestone, now offer nitrogen inflation.
The main advantage of nitrogen inflated tyres is that they deflate at a much slower rate which, in military and motorsport settings, is extremely useful.
Nitrogen inflation is not a necessity for your average motorist, but it could be useful if you don’t check your tyre pressures as often as you should. Aside from being a safety issue, running underinflated tyres also uses more fuel, so having correctly inflated tyres at all times could benefit your fuel usage.
It’s the same story when it comes to wear life. If your tyres are correctly inflated at all times, nitrogen inflation won’t affect the speed at which they wear. But if, like most people, you don’t check your tyre pressures regularly, their wear life could improve with nitrogen inflation. Tyre life can be reduced by as much as 20-50% if you’re running underinflated tyres, but it really depends on your driving and tyre maintenance habits.
NB: It’s highly recommended to check tyres weekly or fortnightly, not just for inflation and wear, but also physical damage like gashing, rim damage and punctures like screws or nails that have not resulted in visible deflation, but may still leak. Nitrogen should never be used to supplement regular tyre checks.
What is aquaplaning and what happens to a vehicle and its tyres when aquaplaning?
Just as an aeroplane’s wings lift up and over air, a tyre can be lifted off the road surface by water. If you drive reasonably fast through standing water, your tyres could lift so there’s no part of the tyre touching the road. You lose all grip and control because you can’t steer, turn or brake.
How does good tread pattern displace the maximum amount of water?
If your tyres have wider and deeper grooves and a more advanced tread pattern, the water is going to be evacuated from them more efficiently. There’s less chance there will be enough water pushing the tyre up to reduce contact with the road.
How much and what kind of testing goes into developing tyre products?
Bridgestone spends around $800 million every year on research and development, starting in a laboratory, looking at different types of rubber and compounds and testing them many times over.
Then we carry out drum testing, to test the tyre’s rolling resistance and durability. At a Bridgestone testing facility that I visited in Japan, if you added up the number of kilometres run during the drum testing, the tyres were travelling around the world six times each day.
We also run indoor lab testing, looking at things like rolling resistance and puncture resistance, and real world testing for handling, stopping distance, traction, grip, ride comfort, wear life – anything you can imagine you might want from a tyre.
What makes up a tyre’s construction and what function do the various materials perform?
All new passenger car tyres in Australia are steel belted radial tyres. They have a radial body ply, which runs from one sidewall, up under the tread, and down the other sidewall. That gives the tyre the strength to hold the air inside. They’ve also got two steel belts, which help keep the tyre in contact with the road and protect it from punctures.
Tyres are made up of many different types of rubber, with the tread rubber being different to the sidewall rubber, the sidewall rubber different to the inner liner and so on.
Bridgestone currently uses a significant amount of natural rubber in its tyres and is constantly looking into different natural alternatives to synthetic rubber. In 2015 for example, we successfully built a passenger tyre with 100 per cent of its natural rubber containing components derived from a desert shrub that grows in arid regions.
How much oil is used to make an average car tyre and are developments are being made to reduce how much is consumed?
The amount of oil used to make a tyre depends on the type of tyre it is. For instance, where truck tyres are concerned, our Bandag re-treading business saves a significant amount of oil.
Tyre re-treading is a highly practical and efficient form of recycling that uses 70% less energy than making a new tyre, saves around 57 litres of oil per tyre and reuses approximately 75% of the original tyre material. If you replace a tyre’s tread instead of making another whole tyre from scratch, you’re saving a huge amount of oil and resources.
Where do we get rubber from to make tyres? Does it grow on trees? 
Yes, natural rubber does grow on trees! The sap contained in rubber trees is natural rubber, which is harvested in much the same way as maple syrup is drained from maple trees. It’s an ongoing process that doesn’t harm the trees, which heal completely. Around 90 per cent of rubber plantations are in South East Asia, which is why Bridgestone’s tyre factories are strategically located in countries such as Thailand and Indonesia.
What innovative tyre design ideas and developments are being conceived for the future of transportation and mobility?
As their desire to use less fuel and be more environmentally friendly grows, consumers are increasingly adopting low rolling resistance tyre technology. Put simply, rolling resistance is the force required to roll a tyre. Lower rolling resistance means less fuel consumption and lower CO2 emissions. For fleets in particular, swapping from a conventional tyre to a low rolling resistance tyre can result in significant fuel savings.
There is continuing heavy investment going into development of the Ecopia low rolling resistance tyre range. 
