tyre test - bridgestone dueler h/t 840
a bridge too far ?
Bridgestone's Dueler H/T 840 Tyres Claim To Be A Great Compromise For 4x4 Owners Wanting A Good On-Road Tyre But Also Needing Off Road Capability. Steve Walker Puts Them To The Test.
The vast majority of off-road vehicles sold in the UK leave the showroom on tyres biased towards road use because the road is where most of them will be put to work. This type of rubber is designed to be smooth and quiet on the highway, while giving precise steering responses and minimising roll in corners. It's a significantly different set of requirements to those placed on an off-road tyre. The question is, can the standard fit tyres on our 4x4s live up to these vehicles' off-road billing and just how much difference can a set of off-road tyres make to performance when the going gets rough?
To find out, we compared the off-roading abilities of a Toyota Land Cruiser shod with road-orientated Bridgestone Dueler H/T 840s with the performance of the same vehicle on BF Goodrich all-terrain tyres. The Bridgestone H/T 840s are typical of the standard fit tyres you'll find on most large 4x4 vehicles and indeed, they've been adopted by a number leading 4x4 manufacturers as standard fitment on their products. The small-block tread pattern is constructed to offer good all-weather grip on tarmac while minimising the amount of road noise and vibration that finds its way into the cabin. The Bridgestone is also stiffer in the sidewalls and in its rubber compound than the typical all-terrain tyre would be. This helps to deliver improved cornering accuracy and stability along with enhanced durability.
To really put Bridgestone's finest through the mill, we arranged a visit to the hills and forests around Eastnor Castle near Ledbury in Herefordshire. The estate is the spiritual home of Land Rover and its meandering, mud-clogged tracks have served as the proving ground for successive Range Rover, Discovery and Defender models over many years. The terrain at Eastnor is not for the faint-hearted or the slick-tyred and the overriding concern as we drew nearer was that bringing the Land Cruiser here on its Dueler H/T 840s was the automotive equivalent of striking out for the North Pole in your flip-flops.
With this in mind, we started gently on a heavily forested loop that we were assured posed little risk of getting stuck. The gradients involved seemed plenty sharp enough but our guides were quick to point out that these were gentle hillocks compared to the precipitous terrain on offer elsewhere on the estate. The Bridgestone Duelers gripped the gravelly soil here without a hiccup, giving the Land Cruiser's Downhill Assist Control the chance to do its thing on the steeper drops and ensuring that the dashboard's traction control light rarely flickered.
Of course, the BF Goodrich all-terrain tyres were similarly composed in this comparatively modest off-road environment. They felt more secure on the descents and at the wheel you felt more confident in the extent in the grip available, enough to put the hammer down and power up inclines that called for a lighter touch with the Bridgestone Tyres fitted. This trail may have been tame by Eastnor Castle standards but it's certainly far in excess of anything that most UK 4x4s will ever encounter. Motorists with an off-road vehicle riding on the Bridgestone Duelers can be confident that muddy farm tracks and steep grassy banks are well within its remit.
Moving on, it was time to test the on-road tyres to the limits of adhesion and beyond. Elsewhere at Eastnor, the surface transforms from stony soil to slick wet clay and here the deep ruts carved buy decades of passing Land Rovers offer little by way of grip, even to tyres designed for the purpose. This type of surface succinctly demonstrated the importance of tyres when it comes to successful off-road driving. Overnight rains had filled the deep gouges in the trail with liquid mud and covered the clay's surface with a slick, silky sheen. The Land Cruiser and its tyres were to have their work cut out.
Perhaps surprisingly, the big Toyota continued to get a grip on these more difficult trails but progress was far more touch and go. On the flat or on moderate gradients, where the ruts weren't of a depth to make ground clearance an issue, progress through the clinging mud was steady but when a rogue root or a steeper incline complicated matters, the Bridgestones' forward momentum would degenerate into wheelspin. On occasions, the impasse could be successfully negotiated with a healthy blast of throttle, other times it became a case of backing up and having a run at whatever was giving you the trouble but we also learned that good offroading is also about knowing when to admit defeat and break out the winch.
The Goodrich all-terrain tyres displayed a higher level of tractability in the clay but you'd expect them to do that. The greater lateral stability provided by the knobbly tread meant that the Land Cruiser was propelled forward with less of the grip that there was being lost to the tyres zigzagging from side to side in the ruts. Having said that, as with the Bridgestones, there were still sections of track that proved impassable to the all-terrain tyred Land Cruiser.
The verdict that the BF Goodrich all-terrain tyres gave better off-road performance than the Bridgestone Dueler H/T 840s was always inescapable from the word go. The interesting thing was how close the roadgoing tyre from Bridgestone came to living with its altogether knarlier rival. Even if you do plan on putting your 4x4 to some tough offroad work, there's a good chance that the Bridgestone tyres could do the job. Really extreme stuff would be best avoided because getting stuck without a winch-equipped support vehicle in attendance is not something you want to make a habit of but the Dueler H/T 840 proved more capable than we would have imagined. Then you've got the added advantage of the tyre's performance in its preferred on-road environment. We wasted no time in switching back to the Bridgestones for the long motorway journey home.