4WD MODIFICATIONS - TYRES & WHEELS
We were very impressed with the latest D697 A/T tyre from Bridgestone, but the mud-terrain D674 version didn’t last well on stony roads – removed after less than 7000km in the bush.
After an excellent run with two sets of Bridgestone’s D697 A/T tyres – 16-inch and 17-inch – we bought a set of the M/T674s to evaluate, having had good results from the previous D673 M/Ts.
The new tyres were fitted to one of the OTA fleet vehicles: a LandCruiser 79 Series and monitored during a desert trip in mid-2015.
The vehicle caried a Tray-Tek slide-on camper and was loaded to 3580kg GVM, as was our own LandCruiser 75 Series, also carrying a Tray-Tek slide-on. We used this trip to check out a set of B F Goodrich’s new KO2 A/T tyres.
Both vehicles drove the same distance on stony dirt and bitumen roads, and through dune country. Both vehicles had Doran tyre monitoring systems fitted, to ensure optimum pressures for the different conditions.
At the end of this 6000+km bush jaunt the BFGs on our ute looked like brand new, showing no cuts or chips and no irregular wear.
In contrast, the Bridgestone 674s looked like they’d been driven through a metal scrapyard.
There were cuts in many of the tread blocks and, much worse, at the base of the blocks. One cut exposed the underlying casing plies (see photo on the right).
We couldn’t believe what we were seeing, because the D697 A/Ts we’ve tested showed no such damage when driven in similar conditions.
When we showed the D674 tyres to Bridgestone the company had no hesitation in replacing them with brand new D697s – no questions asked.
Incidentally, the fitting dealer’s own vehicle was shod with D674 M/Ts that were also showing early signs of block cutting and tearing.
Bridgestone Australia’s engineering team investigated and told us that this tyre was developed mainly for slippery conditions, not for for the stony roads that many M/T tyre buyers drive on.
Bridgestone recommends the D697 for gravel roads and stony area travels and our test experience endorses that position.
The Bridgestone D674 is still the company’s recommendation for extremely muddy conditions, but as our testing showed, it’s not designed for stony gravel.
We’ve read reports on other websites and in magazines praising the outback abilities of the D674, but they’ve either not tested it properly or they’re frightened to upset Bridgestone. At OTA we don’t work like that: we report it like it is.