July 26, 2012

Beyond the low box

Seikel snorkel is a factory option. This Amarok also had Mickey Thompson mud tyres, giving it a big edge over the others on street rubber.
Volkswagen couldn't have chosen a better – or worse depending on your point of view – day to introduce its new eight-speed auto Amarok double cab ute. After days of heavy rain, the farm south of Auckland was really slippery and its creek the highest 4wdNewz has ever seen it. Nevertheless, and as we've now come to expect, modern electronics saved the day and did a creditable job of traction-controlling the trucks around on their street tyres.

But this was more than just another new ute with electronics. The eight speed Amarok has full-time 4WD but no low range. Instead, the first two gears of the ZF automatic are really low, mimicking the kid of ratios you get from a conventional box in low range. Based on some steep downhills (with traction) on the farm, first appears to be similar to that of a typical automatic 4WD with transfer case in low range. That, of course, is not very good compared to a manual. Standard hill descent control (HDC) should bring the ute down the hills slowly and under full control in any gear but was malfunctioning on the ute 4wdNewz drove, and on one other.

Digging into the specs, the Amarok's first gear is in fact nowhere near as low as a typical automatic 4WD. It's 4.714 which, when multiplied by the 3.7 final drive ratio, gives overall low gearing of 17.44. The ubiquitous Hilux has a first gear ratio of 2.804, but its overall low works out as 26.8. Manuals do much better: a decent 4WD will have an overall low of around 45:1. The current Defender manual (and Wrangler Rubicon automatic) can top 60:1

However, there's every possibility that the no low-box off roader with "crawler" ratios will become popular in the quest for lighter vehicle weight and better fuel economy. The Amarok suggests that this might be quite viable, coupled with today's electronics. It's also a no-fuss way to drive off-road, particularly on routes that require frequent swapping between high and low range. On the other hand, it'll take a lot of refining and even lower ratios before the configuration will be a satisfactory low-box replacement for the kind of off-roading many 4wdNewz readers enjoy.

The optional recovery device wasn't needed on the day.

This guy needs to either improve his bow-wave technique, or get a snorkel.

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