Why don't they?

You don’t spend very long reviewing cars before you come up against some design decisions that seem odd, if not downright stupid. Why, why, why did they do that when it’s just so wrong and there’s such an obviously better way?

The answer is at once both simple and complex. You’re looking at the car from a very narrow yet unconstrained perspective, that of someone using a car for a specific purpose, be that offroading, towing, touring, or even assessing just how it looks. If someone else with a different use for the car looked at it they may well not notice your big bugbear and worry instead about something you’d dismiss out of hand as being unimportant. You can do that dismissal, but the car designers must take all perspectives into account.

You’re also blissfully unaware of constraints like costs, compliance with regulations, safety and myriad other factors the designers need to take consider.  It’s easy to criticise from that perspective of ignorance. And of course, errors are made and sometimes are too expensive to undo. Sometimes the errors aren’t even errors, but decisions that were correct at the time yet now constrain what can be done with later models, and most cars are developments of other cars or at least the base platforms. Then there’s the needs of styling, cost, safety, different kinds of performance and many more which are often diametrically opposed – the cheapest car possible would be ugly, unsafe and generally hopeless, and the best offroading design wouldn’t cut it onroad.

The fact is that the modern car is not designed by idiots but by some extremely smart brains, so it’s a unfair to criticise it without that wider context. Or is it? If we don’t measure the car against an ideal, then we’re always accepting and excusing what we get given and that’s no way to progress. Except that car companies aren’t interested in progress per se, but in another p-word and that would be profit. Let’s not get all socialist about profit, because profit pays people and delivers dividends. But a profit focus isn’t going to mean a focus on making the best car available because that would be very expensive – it means a focus on making the most profitable vehicle, which means a balance between progress and cost. This concept of balance is precisely the same for any sort of large, complex construction be that information technology systems, cities, ships or even something small you may have created such as woodwork, knitting or even just cookery. Very few things in the world are designed to truly be the best with no cost or time constraints.

Whatever sort of balance you decide upon, you product needs to have some sort of what’s called a value proposition, or in other terms, a reason to buy it. That can be value, cost, service, features or anything else and it is determined by analysing what is likely to sell the most cars for least investment.

And that brings us nicely to the subject of dual-cab 4X4 utes, which as it stands are something of living history. The big five are the Ford Ranger, Toyota Hilux, Volkswagen Amarok, Mitsubishi Triton and Nissan Navara. The Mazda BT-50 is the same vehicle as the Ranger, and there are other utes such as the Land Rover Defender, Nissan Patrol and Toyota 7x but those are a different class. It’s the first five that are direct competitors, and what your competition is doing is a big factor in any product development. And they aren’t doing as much as they could be. All of these utes have old-school design of leaf springs, a live rear axle, drum brakes and part-time 4WD. All could be hugely improved if they had coil springs, independent rear suspension, disc brakes and all wheel drive. But why?

Leaf springs are crude. They rub together when compressed and extended, unlike coils. That rubbing creates friction, which acts as a natural damper. Problem is, there's already a damper in the shape of a sophisticated shock absorber which is finely-tuned to precisely control the suspension. A leaf spring is not, hence a less pliant ride. The leaf spring also locates the axle relative to the chassis, and it doesn't do a great job as it is by definition a spring which has some give, not fixed like the arms used for coil springs. Leaf springs also protrude in front of and behind the axle, which tends to get in the way offroad. Finally, leaf springs are prone to getting debris between the leaves which increases inter-leaf friction at the expense of ride quality. And the leaves fitted by manufacturers are not exactly the last word in leaf spring design, lacking greaseable shackles and poly bushes.

Independent rear suspension provides much better handling than a live axle because each wheel is relatively unaffected by bumps in the road, and you can tune the suspension with settings like camber. From an offroad perspective the suspension travel may not be so great, but look at the current crop of utes – the rear end flex is hardly impressive as it is, and an independent suspension also moves the diff up out of the way, giving more clearance in the centre of the vehicle. Finally, sheer suspension travel isn’t the huge advantage it once was, as with modern traction control cars can keep moving even with only two wheels on the ground. The more flex you have, the closer the chassis to the ground so there’s an argument for independent suspension and good traction control over long-travel suspension. In fact, the Discovery 3/4 and similar Land Rovers are proof this design concept works.

Disc brakes are better than drums. The purpose of a brake is to slow the car down by converting kinetic energy into heat, so it follows the most effective brakes are those that most effectively dissipate heat. Disc brakes are much better than drum brakes in this respect because they are more open to the air. And from an offroading perspective drum brakes are prone to fill with mud and debris, requiring regular cleaning. Disc brakes don’t have this problem.

Finally, there’s all wheel drive, and a nod here to the Triton which offers it, and the Amarok which can be had with VW’s 4Motion but not with low range! The rest don’t offer AWD, which means the ability to drive all four wheels even on high-traction surfaces, as opposed to part-time 4WD which can be only used on low traction surfaces like dirt roads.

All wheel drive is important because it provides significantly more grip when accelerating or cornering, and even helps when braking. The reason is simple. A given road surface has say X amount of grip. The car can produce, through its engine and gearing, Z amount of torque (turning force). If the amount of torque exceeds the grip level available then the wheels will spin, leading to a potential loss of control, certainly loss of speed and increased tyre wear. All that power is not being effectively used.

So let’s say we’ve got a 2WD, and that torque, Z, is then divided by two, and with the ever-increasing power of utes that may well exceed the grip, X. But with AWD that torque is divided by 4, so the chances of Z exceeding X are much smaller, or another way, the car can accelerate on lower-grip surfaces without wheelspin.

Cornering is exactly the same as accelerating. To maintain speed around the tyres must provide a cornering force and some acceleration force, otherwise the car would slow down. Tyres have only a given amount of grip, the X again, but when cornering some of that grip is being used for turning, leaving less for accelerating or countering the natural slow-down effect of the car. A rear-wheel-drive ute places heavy loads on the rear tyres as the acceleration force comes purely from the rear tyres, and even worse, because there’s less weight on the inside wheels those are most prone to spin up. All wheel drive solves the problem by dividing the driving force by four, so there’s more of each tyre’s grip available for cornering.

Braking can even be assisted with all wheel drive in slippery conditions if you use the engine to slow down, as again you’ve got four wheels doing the work, not just two.

The AWD/2WD problem is particularly acute for utes because of their leaf-spring, live-axle design, and the fact their suspension is designed for a heavy load and thus not particularly able to soak up road imperfections and transmit power to the ground. In days gone by when utes had four speeds and just enough power to move off without a push this didn’t matter. Now we’ve got utes of 150Kw+, and that’s just the diesels, along with six and even seven speed automatics. In short, the engines are now writing cheques the chassis can’t cash.

So why is this the case? The answer has already been given, and that’s cost-effectiveness. Although the basic hardware is in place – front differential, propshaft and the like – the ute manufacturers haven’t gone the one step further and added a centre differential or similar to make all wheel drive, with the exception of the two cars already noted and the reason is simple -  buyers of utes don’t care about all wheel drive. What they care about is power, torque, styling and towing capacity. That’s why Nissan are bragging about the Navara’s 550Nm of torque, and even named the car after that figure for that very reason.

The potential buyers don’t care much about disc brakes, all wheel drive or coil springs. In fact, many of them would consider an independent coil ute a disadvantage, because that’s equated – wrongly – with not being able to carry a load, and not being as good offroad. Power, and to a lesser extent torque have been defining selling points for Australian cars marketed to blokes as can be seen by the importance HSV and FPV place on output figures. Whether on not that output can be usefully put to the ground seems to be of less importance. After all, imagine the conversation – how many blokes are not going to buy a ute because the back end might step out under power and say "well, I'd rather something easier to control, thanks".   Actually, there’s no “might” about it, the modern diesel ute will chip tyres in the dry, especially when turning right at a T-junction and always on dirt roads. In the wet you’re guaranteed traction loss and you need not be going that hard either. Personally, I think all wheel drive is well overdue for all utes, but this post is about the reasons why it’s not already here.

The other factor is your competition. If Toyota and Nissan had gone all wheel drive then Ford would have done too. But as it is, the situation is almost like a cartel where they’ve all agreed that they won’t do it so they can all sell the cars at greater profit margins and nobody takes that leap forwards. The American auto industry got very rich on the backs of the likes of the F-trucks which were a large, simple, cheap vehicles sold for quite a lot of money and I’m wondering if the space strategy is at play in Australia with our utes.

So the ute manufacturers are only doing what makes commercial sense, which is producing the car that is the best balance between development cost and sale volume. Manufactures do whatever it takes to sell, regardless of whether it’s actually a good idea or not. Other examples have been the camera industry’s ever-increasing push for more megapixels, because the consumers had an idea that more was always better, and the computer industry’s one-time focus on processors with higher clock speeds measured first in Mhz then Ghz.

The reason that such simplistic measures are focused on is because humans like to reduce complexity. The performance of a camera is a function of many complex design features such as lens quality, signal processor, software design and much more. But it’s easier to boil that down to the number of megapixels, which is easy to understand and compare. Similarly, the performance of a ute is complicated and multi-faceted, but boil it down to a simple engine output number and you’re got an easy comparison point. The fact that a peak output doesn’t mean much without also account for weight, torque curves, gear ratios and much more is a complication that doesn’t worry the buyer, and therefore it doesn’t much worry the manufacturer.

The same is true of wagons, and I think here of the Discovery 3/4's insane parkbrake design and crazy requirement to raise the third row before you can drop the spare wheel.  Neither changed in the update from 3 to 4, and why not?  Because Land Rover decided it wasn't cost-effective to change as they wouldn't sell any more cars by that change, and the effort would be better directed elsewhere.  As a touring offroader, the fact is we're in the miniority and that's just commercial reality.   Still, it won't stop be having a crack at the manufacturers whenever I find something not suitable for touring, even if I do get the bigger picture.

Of all the five utes the Triton was the first with all wheel drive, and you may wonder why. The answer is in the closely-related Challenger, which shares much the same front end, but is a wagon and therefore competes in a different market. The wagon market really does want all wheel drive and coils, so that’s what the Challenger has. Once developed there, Mitsubishi decided it may as well go in the Triton too, and good on them. It’s a pity Nissan didn’t do the same with the Navara/Pathfinder duo, and let’s hope that if Ford develop a wagon variant of the Ranger then they’ll give their ute all wheel drive, if not fully bring it in to the 21st century.

Related links

• Why AWD is better in winter
• Ford Ranger 2012 Review
• The 2012 Ute Market
• Ford Ranger 2012 Electronic Driving Aids

* Yes, I know this is a simplification and I should be using terms such as coefficient of friction, optimum traction slip ratios and so on, the grip levels aren’t exactly the same across all four wheels, particularly when accelerating. But the point is made anyway.