June 12, 2011

Why the fat's piling on, and what we can do

The following was written by Robert Pepper, author of the 4WD Handbook. It appeared in the latest issue of the United Four Wheel Drive Association's online magazine, Voice. I'm printing it here because it goes a long way to explain why today's 4WDs are the way they are and what's wrong with some of our accessories.

You can’t have missed it. Over the last few years the car industry has changed colour, going all eco-green and environmental, caring, sharing, cuddly and keep-cup responsible. Lower fuel consumption, emissions offsets, hybrids … it’s all there in the new, softer, auto industry. Well, most of it, anyway. Certainly the new-car makers have completed their road to Damascus conversion, but there’s a sector of the industry that’s lagging. What have accessories such as bullbars, roofracks and the like got to do with being green? The answer is weight – simply, the heavier your accessories are the more fuel you’ll use and the worse the vehicle’s performance, on and off road. The fuel issue may only be of secondary concern to many consumers, and indeed if it was a real worry then the industry would have responded by now. 

But even if you don’t care about fuel and its close relation, range, you should care about roadworthiness. The sad fact is that if you put the usual accessories on the average 4WDwagon, and then get in yourself, you’re generally going to be pretty close to legally overloading the vehicle. In technical terms, that’s exceeding the GVM, or Gross Vehicle Mass, the heaviest amount the vehicle is allowed to weigh by law. What the vehicle can carry is the payload, which is the difference between the empty (tare, or kerb) weight and the GVM. The payload is being squeezed; time was that 4WDs were mini-trucks, with mini-truck carrying capacity. Nowadays they’re more car-like, and there’s a plethora of heavy additions – compare the 60 Series Cruiser to the 200 and you’ll see a host of electronics like ABS and stability control, then there’s advanced crush cells, more soundproofing and the list goes on to add well over half a tonne more weight for roughly the same size vehicle. Of course, the 200 outperforms the 60, due to all those electronics and a massive increase in power, but that’s despite its bulk, not because of it. 

Apparently, the human race is also more lard-arsed as time goes on, so that doesn’t help either. Hence we have the problem of accessorising a vehicle and using up far too much of its payload in the process. So what can be done? As a consumer, just be careful about your weights and, if necessary, go on a diet. The bigger question is what the accessory manufacturers should do, and that answer is clear. In the old days it was enough that the product worked. Now consumers demand form as well as function; the likes of bullbars must be styled, and everything has to look good, not just work. The stage beyond that – which we’ve not quite yet reached – is adopting the Lotus approach of “adding lightness” – accessories need to look good and weigh as little as possible. So far, there’s not much evidence of the aftermarket adopting this mantra and there’s a good reason why: few customers ask, sometimes because they don’t care to know, but mostly because it doesn’t occur to them that they should. When that changes, and it will, then the green tinge will wash a little further.


  1. What ar you saying, that we should all change ova to crappy ally bumprs and bullbars. What a bunsh of BS.

  2. We alredy no all this just look at purpose built winch trucks and trials trux