Get a grip with tyres
Good-quality off-road tyres are one of the best ways to improve the performance of your four-wheel-drive. To clarify the options, we spoke to industry expert Jeff Newick, at Cooper Tires, who explained there was a big selection of brands and tread designs available.
Newick broke tyre patterns into four categories: highway, all-terrain, aggressive all-terrain and mud.
Highway terrain tyres have a closed-in tread pattern for quiet operation. In most cases there’s a solid centre rib aiding stability at highway speeds with siping (small cuts within the tread blocks) for wet-weather performance and a see-through tread design for better water evacuation.
These tyres are typically designed for 90 per cent use on-road and 10 per cent off-road in easy-compact, moderate conditions.
Cooper tyres have tread patterns for on-road and tough off-road challenges. Picture: coopertires.com.au
All-terrain tyres have a more aggressive pattern and most feature a broken centre rib for better soft-surface traction. They have a more open tread design for clearing dirt, mud and debris, and better allow the tyre to work in sloppy conditions. The siping is limited to within the tread blocks to reduce chipping in off-road situations.
Use these for a mix of 70 per cent on-road and 30 per cent off-road use, as ATs have better soft-sand traction, improved self-cleaning and are more stone resistant.
Newick’s top tip is to look for a pattern with different-size tread blocks around the tyre because this breaks up the harmonics of the tyre, making for quieter operation.
An aggressive all-terrain pattern is mostly classed as a 50/50 on/off-road tyre. These tyres have even stronger carcass constructions perfect for heavy off-road work. The aggressive AT pattern is even more open with stepped shoulder lugs for traction.
They should have an enhanced upper-sidewall buttress for abrasion resistance from objects plus stone ejectors between the shoulder lugs to ensure stones do not drill into the case and cause damage to the steel belts.
Mud-terrain tyres have a very aggressive tread pattern and soft-tread compound with an expected use of 20 per cent on-road and 80 per cent off-road. This is a “digging tyre” designed to cut and bite into the mud for grip and then self-clean to enable grip to be maintained.
Good-quality MT tyres should be a three-ply carcass construction, have stone ejectors and side biters for extra traction when in ruts or at low-pressure operation.
This pattern is naturally noisier in operation but, if maintained properly, they shouldn’t sound like a DC9 bearing down on you.
Newick recommends choosing light-truck construction if it’s available for your vehicle, rather than passenger. This provides a robust carcass with stronger steel belts for better durability and improved weight-carrying capacity. They should also provide deeper tread depth for longevity and a higher resistance to punctures when running appropriate pressures for the terrain.
© The West Australian
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