Test 3: Trac­tion in sand:

Road Trip - - GEMS TRIP -

This test was a make or break af­fair.a 600 kg Jur­gens XT140 off-road trailer was loaded with 150 kg (thus 750 kg in to­tal) and hitched to the Ranger. The bakkie had to pull its own weight and that of the loaded trailer through a pre­pared sand track with a 10-de­gree in­cli­na­tion. The con­trol Ranger, with tyres de­flated to 1.4 bars and all elec­tronic sys­tems switched off, drove the track un­til it got stuck. The start­ing point was then set from the point where the ve­hi­cle barely made it through the course. If any of the test tyres suc­cess­fully ne­go­ti­ated the course, the con­trol mark was to be moved for­ward un­til the test ve­hi­cle did not make it any­more. In this test the new Wran­gler AT Ad­ven­ture showed its met­tle – set­ting the bench­mark nearly three me­ters clear of its clos­est chal­lenger. The new Gen­er­als, the GT Ra­di­als, and the new Dun­lops also fared well, while the gap be­tween the BF Goodrich, the Miche­lin, and the Bridge­stone tyres were achingly small.

Test 4: Gravel ac­cel­er­a­tion:

The ob­ject of this test was to mea­sure trac­tion on a loose gravel sur­face with the tyre pres­sures low­ered to 1.4 bars. It en­tailed an ac­cel­er­a­tion test (foot flat, all elec­tronic sys­tems dis­en­gaged), mea­sur­ing the time it took each set of tyres to pro­pel the Ranger to 80 km/h; the ra­tio­nale be­ing the bet­ter the grip and trac­tion on this sur­face, the shorter the time needed to reach the de­sired speed…

As to be ex­pected, it was a close af­fair, with all the times of the tyres – ex­cept the Kumho – sep­a­rated by less than a sec­ond. The best per­form­ers were the Conti, beat­ing the Gen­er­als by a hun­dredth of a sec­ond, with the Fire­stone, Nexen, Pirelli, Miche­lin and BF Goodrich tyres also do­ing well.

Test 5: In­cline trac­tion test:this

test – de­vised to chal­lenge the climbing abil­ity of the tyres against an in­cline – turned out to be a real tiebreaker.the Jur­gens trailer was again hitched to the Ranger, and the bakkie then had to pull its own weight, and that of the loaded trailer, up a steep in­cline in first gear lowrange at 2 000 rpm, with all trac­tion con­trol sys­tems switched off. If a tyre com­pleted the as­cent, it scored max­i­mum points, while tyres that did not make it, were pe­nalised with 2,5 per­cent (the av­er­age per­cent­age dif­fer­ence in the other tests).

How­ever, some tyres ac­ti­vated the safety over­ride on the elec­tronic brake dis­tri­bu­tion of the Ranger and sta­bil­ity con­trol sys­tems while scrab­bling for grip, and we de­cided to deduct 0,5 per­cent in th­ese cases.the Dunlop Grandtrek AT3 Gs, Ve­loc­ity Rap­tors and Hankook Dy­napros sur­prised by claw­ing their way through the test, while four tyres – the BF Goodrich, Yoko­hama, Pirelli, and Kumho – did not make it.

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