Comment 6641

By Scheinwerfer (registered) | Posted May 11, 2007 at 13:57:58

You raise some indisputably valid points in this article, Dr. Mitchell. However, your credibility is dubious when you advocate for unit-body construction of trucks and vans, for a few reasons. Two of them have already been discussed by others: the existence in the market of unit-body SUVs, and the unsuitability of unit-body construction for many types of service into which pickup trucks are legitimately placed.

The additional problem I see is that you evidently didn't carefully research the history of vehicle construction methods and trends in North America. You write, inter alia:

"In the mid-1970s, cars [were constructed with] body-on-frame, non-independent rear live axle on leaf springs. Five to ten years later, coil springs replaced the leaf springs [...] big benefits had to wait for the unibody frame. By the mid '80s, unibody cars started showing up in numbers [...] By the early '90s, cars were nearly all unibody."

There are significant errors here-

1) "Unibody" is a trademark, not a generic term. This is admittedly a minor point, but if you're after a generic term for the unitised construction you are referring to, use "unit-body" or "monocoque". The former is more commonly used in North America, while the latter is favoured in Europe.

2) Mass-produced unit-body vehicles were first offered for sale in North America in the mid-late 1930s by Chrysler Corp (the Airflow models). These didn't sell well due to their unconventional styling. The second attempt -- this time a successful one -- in North America happened in 1960, twenty-five years before your "mid 1980s" figure. And the unit-body vehicles that arrived in the early '60s weren't just a few exotics, either. Chrysler Corporation introduced the unit-body Valiant and Dart models in 1960, switched their entire passenger car lineup to unit-body for 1962, except the Imperial which was switched to unit-body for 1967. These cars were very popular and highly rated by consumer reviewers (who liked their durability, reliability, and handling-related safety characteristics) and motor-trade reviewers (who liked their performance-related handling characteristics). Ford introduced their unit-body Falcon in 1960, and offered an increasing number of unit-body cars after that date. And there are numerous other examples as well. Certainly there were plenty of body-on-frame cars being sold in the mid '70s, but there were also plenty of unit-body cars at that time.

Furthermore, good unit-body designs did not suddenly materialise in the late '80s or 1990s as you claim. As you must certainly know, even the most elegant engineering concept is only as good as its implementation. There were many poorly-designed unit-body vehicles in the 1980s and 1990s for reasons having more to do with overly cost-averse manufacturers than with the (nonexistent) novelty of the concept.

3) Your comments regarding coil vs. leaf springs have some validity, but not as much as you seem to think. There are many variants of the three primary types of automotive suspension springs (coil, leaf, torsion bar). The simpler, less-costly versions of each tend to have a narrow load window through which handling can be considered "good". Additional refinement tends to improve the baseline handling, widens the load window, and increases the cost -- no matter whether the system incorporates coil, leaf, or torsion bar springs. As with unit-body vs. body-on-frame construction, the devil is in the details (or, more to the point, the handling quality is largely down to the implementation rather than the concept).


There is a definite mismatch between what is offered and what is genuinely needed by most buyers of trucklike vehicles (i.e., a passenger cab + cargo box). Remember the Chevrolet El Camino and Ford Ranchero and Subaru Brat? They were car-based trucks, essentially station wagons with a cargo bed instead of a station wagon body with rear seats and a tailgate. You can't get them any more in North America, but Australians can still buy car-based RWD pickups, which offer safety, fuel efficiency and cost-effectiveness vastly superior to truck-based pickups, while remaining amply capable of handling the needs and wants of what most individuals buy pickups for. "Utes", they call them, short for "Utility". See Ford's at and GM-Holden's at , for example.

So, why don't we have those vehicles here? Marketeering plays a part, but there are larger forces at work. Through the early '70s, the North American vehicle market was a pure oligopoly, i.e., it was fully controlled by GM, Ford, Chrysler, and if we're being generous, AMC. Now we've got all the world's biggest automakers selling cars in North America, but the oligopoly still exists in a more insidious form: US vehicle equipment and construction regulations (and the Canadian standards forcibly kept nearly identical by the US auto industry's "free trade" tactics) are based almost entirely on SAE standards, which were written almost entirely by US automakers. Vehicles conforming to the internationalised (originally European) ECE regulations are allowed or required throughout the entire rest of the world, but such vehicles are banned from North America because they don't conform to the NA regulations.

The claim is made (or at least strongly implied) that ECE vehicles aren't as safe as NA-spec vehicles, but a mountain of high-quality data shows that is not the case. If it were, the US would have the lowest number in the world of deaths and injuries per vehicle-distance travelled and per vehicle registered, and that is not the case. The US is #16 on one list, and #10 on the other. Canada (where vehicle regs are almost identical to US) is a few slots better on both lists, because Canadian seatbelt usage rates are over 90% compared to around 70% in the US. But neither country is at the top of the list. All the countries higher (better) on the list use ECE vehicle regulations, not the NA regs. That doesn't necessarily mean that if all vehicles in North America were magically transformed into ECE compliance overnight our safety would improve, but it does mean the NA regs don't do a better job than the ECE regs, and there is no safety-related reason for banning ECE vehicles from North America.

So...why are they banned? Easy: They are banned so that the US automakers (including the US operations of foreign brands) can continue to control what vehicles do and don't enter the North American market. We have decided to buy into the highly questionable notion of "free" trade, so tariffs and local-content laws and other ways of protecting domestic jobs and industry are now considered backwards and taboo. As a result, we hide our trade restrictions in technical regulations, claiming the need for different regulations is based on safety while excluding vehicles demonstrated to be safe in countries like Germany, the UK, Australia, and other countries with faster, higher-density traffic and fewer deaths and injuries on the road.

There are lots and lots of vehicles we don't get in North America that consume less fuel while doing as well or better at serving the needs and wants for which we buy vehicles. That is because in other countries, fuel is taxed at higher rates, so people have more personal incentive to demand fuel efficiency. And I'm talking about all classes of passenger cars, SUVs, pickup trucks, and vans, not just microcars. But, the cost of certifying a vehicle to North America's different-but-not-better safety standards is immense -- multiple millions of dollars -- and so those vehicles aren't allowed in this market.

Why? Follow the money!

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