TYRE TOPICS

Choosing the right tyre makes all the difference

It’s an unfortunate fact of life that, on a scale of one to ten, tyres don’t seem to attract a high level of excitement on the part of the buyer. Purchasing tyres is seen as a grudge activity, where the buyer knows that good rubber on each corner of their vehicle is important for safety reasons, but there’s a misguided expectation that low-priced tyres will provide almost the same levels of safety as a set costing up to twice as much.

As with everything you encounter on the road of life, you get what you pay for. While the customer understands that there is a high level of technology abundant in the car they purchase, they seldom extend this belief to the round and black rubber fitted to each corner.

Well, just to repeat, you get what you pay for.

The technology that goes into the research and development of a new tyre is quite staggering. Up for contest is the ride quality and handling capability, the wet weather performance in the rain and the need for long tyre life in the dry. The tread compound has to provide the highest level of grip, but at the same time, it needs to have inbuilt longevity, preventing premature wear rates.

Each type of tyre has a different objective. If you travel on dirt roads there’s a need for all the ride and handling, cornering and brake ability you can pack into its design. It has to resist the prospect of stones being abrasive and cutting or chipping at the tread pattern where it promotes excessive wear. It must prevent the entrapment of stones within the tread pattern that translates into stone punching as each rotation of the tyre hammers the stone into the casing.Tyre_Topics_11

If you travel on muddy terrain the tread pattern has to be self cleaning, flinging the mud out of the tyre tread on each rotation of the wheel, effectively cleaning its own tread in order to gain maximum traction. The same applies to use in heavy rain, there the sipes or small grooves of the tread syphon away the water, preventing it from collecting between the tyre tread and the road surface where it lifts the face of the tyre off the road at high speed, causing loss of traction or grip that we call aquaplaning.

Fortunately there is help at hand, because while you may still not yet be warming to the idea of getting up close and personal with your tyre choice, your local tyre specialist is made of stronger stuff, knows the benefits or pitfalls of each tyre make and tread pattern design, and can recommend the right mix for your car or ute.

When visiting your local tyre specialist make sure you provide the right information about the types of road surface on which you travel. If you are running a light commercial vehicle such as a ute or van then mention how much load it usually carries.

When selecting the right products for our tyre testing these are all factors that we discuss with the experts at our local Tyrepower service centre.

Delivery Magazine currently monitors the tyre fitment and performance on three of our fleet vehicles, two of these being Land Rover Defender 90 4x4s and the third being a current model Isuzu D-Max space-cab.

In order to provide an interesting point of difference, especially with two identical vehicles, we fitted tyres of specific abilities, one aimed at on-highway running, the other suited for a mixture of on and off-highway application.

On Defender 1 with an odometer reading of 41,800 km we fitted the Falken WILDPEAK H/T with a size of LT235/85R16. The WILDPEAK H/T is an all season highway performance tyre designed to offer a combination of dry handling and responsive wet braking on all roadway surfaces. The tread depth when supplied new is 13 mm, and it rotates at 395.1 revolutions per kilometre.

With its non-directional tread pattern, Falken claims it is optimised for traction and control, through its combination of a high-tension casing ply and stiff wide steel belts. This construction promotes stability and comfort with a high mileage tread pattern that combines optimal ride comfort for on-highway application.

A close look at the sidewall tells more, in the form of a maximum load rating of 1380 kg with maximum inflation pressures of 550 kPa (80 psi) and a tyre load index rating of 120Q (1400 kg/160 km/h).

Tyre tread patterns are very specific, and the ranking out of a maximum of five points as shown on the Falken Tyres website rates the H/T as 4.5 in dry handling, 5.0 in wet handling, a tread life of 4.0, an off-road performance of 3.0, towing performance of 3.5 and a snow performance of 3.5.

On Defender 2 we fitted Bridgestone Dueler A/T 697 in a matching size to the Falken at 235/85R16LT and with an odometer reading of 48,800Tyre_Topics_3 km.

There are four distinctly different members of the Dueler family, covering applications of mud terrain, all terrain, highway terrain and highway performance.

Bridgestone ranks the A/T 697 as the ultimate 4WD all-terrain tyre. Its proven superior wear life and better resistance to cutting and chipping make it the number-one choice for all-terrain adventuring. Dueler A/T 697 offers longer life on and off-road, tougher construction for superior puncture resistance, and a quiet, comfortable ride on any terrain.

This is a light truck tyre construction with a thicker gauge sidewall and casing components for improved puncture resistance with a cut and chip-resistant tread compound supported by two heavy-duty steel belts with a full-width protective nylon ply for extra protection against staking and to provide improved durability. A narrower shoulder lug and redesigned shoulder block shape is claimed to reduce noise and irregular wear patterns.

When comparing the tread appearance between the Falken H/T and the Dueler A/T it’s obvious the Bridgestone features a more aggressive tread pattern while the Falken is more attuned to highway work. This fitted in with our requirement and enabled us to compare the two different concepts.

Both tyre designs achieve commendably low on-highway tyre noise and this immediately indicates the sophistication of the tread design and compounds.

It’s this low noise level that indicates the extent of the technology and development that went into both designs, with each offering low steering effort and excellent directional stability.

Test vehicle number three is the Isuzu D-Max space-cab ute.

After completing 34,000 km on its original fitment Bridgestone Dueller A/T sized at 245/70R16, the tyres showed an even tread depth of between 4.5 mm and 5.0 mm across the face of each tyre.

The next tyre change came in the form of a set of General Grabber AT2 tyres designed for a mixture of on and off-highway work, featuring a more aggressive tread pattern than the original fitment. The maximum load permitted for each tyre is 1380 kg in single tyre application (rather than dual-tyre fitment) and at this top weight range the maximum pressure is 80 psi (550 kPa) when cold.

In a world where so many components these days are sourced from China, the sidewall information showed these had been produced in Mexico, a country rapidly becoming popular with the major truck manufacturers as an alternative to production in North America.

At a size of LT 245/75R16 there was a slight difference in rolling circumference by comparison with the previous OE fitment, but not enough to cause concern when it came to contributing to an inaccurate reading from the speedometer or odometer.

In order to minimise the risk of vehicles exceeding the speed limit, vehicle manufacturers usually err on the side of caution with its gearing. This often results in an indicated 100 km/h on the speedo actually showing up to 6.0 km faster than its real speed. We checked the accuracy of the D-Max speedo against a sat/nav unit after the tyre swap and found that tolerances were actually tighter than with the previous tyres, resulting in an indicated reading of 100 km/h being just 2.0 km above the actual speed.

The load and speed index of the 245/75R16 is 120/116S with a diameter of 30.5 inches and a weight of 22.1 kg. The tread depth of 12.7 mm is greater than that of the original equipment Bridgestones, prompting the expectation that unless the wear rate occurs faster, as can be the case with a softer tyre rubber compound, these tyres should exceed the life of their predecessors.

Tyre_Topics_2For those that are interested in heritage, the General Tyre Company was purchased by Continental Tyres back around the 1980s and it remains today a separately branded range under the Continental banner.

The Grabber AT2 is described as having an innovative tread design that promotes high levels of road traction, meets severe snow service requirements and provides exceptional traction over all terrains. The aggressive self-cleaning tread pattern enhances off-road and wet traction capabilities but manages to remain relatively quiet during on-road highway driving.

The full description of the tread design refers to an extra deep, five-row pattern with multiple traction edges, featuring a highly engineered acoustic tread pattern. A further attribute for those heading for the snow country is that the tyre is snowflake approved and can be fitted with studs for extreme use in snow.

Our local tyre experts, Tyrepower at Bowral, looked after the tyre swap, balancing each tyre at the time of fitment. The Grabber AT2s did get the thumbs up for the manufacturing integrity for being obviously round, something that apparently not all tyre manufacturers manage to achieve. Perhaps this is another reason to go for a well-known manufacturer rather than an unknown brand from China.

Our first on-road impression of the Grabbers had been that of slight tread noise at low speeds around 30-40 km/h, but as the speed increased the road noise seemed to reduce. At maximum highway speeds it was not noticeable at all.

And now to wear rates.

The Falken WILDPEAK H/T in a sizing of LT235/85R16 and with an odometer reading of 49,000 km had travelled a total distance of just 7200 km and showed a consistent tread depth across the inner and outer tread section of 12 mm, with the centre section at 11.0 mm. The original tread depth when new is 13 mm and it is running consistently on highway routes only.

The Bridgestone Dueler AT in the same sizing of LT235/85R16 with an odometer reading of 55,511 km had travelled a total distance of just 6700 km and showed a consistent tread depth across the inner and outer tread section of 11.5 mm, with an identical centre section at 11.5 mm. The original tread depth when new is 12 mm and it operates currently on 95/5 ratio of on-highway/off-highway use.

The General Grabber AT2 in its LT245/75R16 sizing with a vehicle total odometer reading of 73,000 km had travelled a total distance of 41,000 km and showed a consistent tread depth across the inner and outer tread section that was now borderline in terms of tyre life. The rear drive axle tyres were also showing signs of stone chipping of the remaining tread pattern, having been operated on a typical 70/30 on-road/off-road use. The original tread depth when new is 12.7 mm.

The Next Stage

When replacing the Grabber AT2 tyres on the Isuzu D-Max we were keen to look at further technology available from Falken and to compare the WILDPEAK H/T highway pattern tyres fitted to the Land Rover Defender 1 with the all terrain version called the Falken WILDPEAK A/T.

We stayed with the same sizing as the Grabber AT2s at LT245/75R16, and, for the record, the tread design is listed as being M+S (Mud and Snow), with a 10-ply rating of 120/116Q.

The Q designates a maximum road speed of 160 km/h and the casing has a maximum load rating at 120 for single tyre application that relates to 1400 kg at a maximum tyre pressure of 80 psi. When supplied as new the tread depth is 12 mm and it completes 428 revolutions per km.

The WILDPEAK A/T has a symmetric five-rib pattern and rigid block design aimed at providing ultra durability, exceptional on-road response and optimised off-road handling. Two stiff extra-wide steel belts enable stability, while four wide multi-angled grooves enable maximum water, mud and snow evacuation.

Falken claims the block edges provide additional traction and control and the variable block shoulder design reduces tyre noise.

Our local Tyrepower branch at Bowral in NSW fitted up the new set of WILDPEAK A/Ts at the same time completing a full wheel alignment. In terms of first impressions, the technology of this Thailand-manufactured tyre showed through by way of low on-road noise levels, and the steering precision was not prone to influence from the road imperfections, promoting direct cornering and controlled handling. In the months ahead the Delivery team will report back at regular intervals with details on performance, tread life and handling ability.

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