Here at Adventure 4WD we clock up some serious kilometres in a year and often on some of the roughest roads going. Added to that are demands placed on a tyre delivering 4WD training sessions that absolutely rip the living daylights out of tread condition and life. Some of the most demanding of those sessions are seen on the Defensive 4WD programs we run. It’s on these courses where the tyre is subjected to huge and repeated stress delivering emergency crash stops at 60, 80 and 100 kph time and again in rapid succession on dirt and on bitumen. Couple that to swerve and recover steering illustrations, again hard under brakes, laterally tugging the tyre to the limits of its adhesion.
In the case of the crash stops it’s usually an exercise in destroying tyre life as the ABS chirps in with maximum deceleration. Despite the near lock-ups our D697s have proven durable. We’ve seen around 80,000kms with no drama which was our experience with Bridgestone’s previous effort the D694. You see we’re firmly of the opinion that Bridgestone have got their rubber chemistry right.
The off-road isn’t kind either and with Adventure 4WDs base in South Australia we see plenty of Outback and coast from the drivers seat of the Navaras. Just in recent months the D697s have had to endure a hike over and back to Fowlers Bay, to the Flinders Ranges on four occasions, the Coorong twice and numerous near-daily in-betweeners to our training property in the Barossa. Each time we’re asking a tyre to do a LOT. Where from our experience the likes of Cooper, Mickey Thompson and BFG have failed through tread block disintegration, our D697s have soldiered on with no punctures and with tread faces worn evenly and with NO chipping or tearing. There’s a big difference between running down a concrete highway in America,
to covering a thousand kays a day on an Outback track and that’s where Bridgestone’s engineers got the rubber mix right. With a compliant rubber tread that yields to the environment it takes serial punishment in its stride!
Of course the nut behind the wheel has a lot to do with tyre durability and I have to tell you that after twenty years in this business we have learnt a thing or two. Tyres aren’t cheap and when we buy a set we want to know they are going to go the distance. Probably the biggest single issue is pressure when you’re talking durability and it’s surprising how many people get that wrong. Plenty would argue we under-inflate here at Adventure 4WD when they hear the pressures we run, but the proof’s in the pudding. No punctures and 80K sound like pretty economical tyre life to me!
Pressure relies entirely on load and speed and once you know the formula it’s possible to replicate our experience. A 20% reduction in pressure from placarded road settings fixes most made dirt roads, whilst a 50% reduction will usually cope with sand and mud and somewhere in between will cope with a lot of rock. In each case though being ready to go down even further will help the cause AND an accompanying reduction in speed. Add careful attention to wheel balance, alignment and rotation and you’ll max-out tyre life (I should mention too that that 80K was done using only the four road wheels – the spare is still tucked up under the tray unused – imagine if we’d used all five, I reckon 100K + would have been easily possible).
Bridgestone asked us to trial a tyre pressure monitoring system (TPMS) in our cars. The “Orange” branded TPMS, is a basic system with four channel monitoring that keeps an eye on all four road wheels via a radio sender/receiver arrangement. The LED display in the car is bright and visible in all lights and will read both psi and kPa measurements. We all agree that it’s a great asset and makes our job really easy when we’re changing pressures to suit the terrain, or when keeping an eye on pressure creep and are of the opinion it should be part of every 4WDrivers kit of essential gear.
After twenty years in business we’ve used and roundly abused Bridgestone’s Light Truck 4WD range. from the original Desert Dueler the D604 and the legendary skinny the D661, to the D693, D694 and now the new hero D697, we’ve had a charmed run with a tyre brand that really is the right stuff for the tough stuff!
Pic: Bridgestone’s ace installers Andy and Chris are full of beans after seeing the A4WD Navara looking like new again… check out those shiny D697s!