Rear Drive Resurgence

There is little doubt that some of the most exciting cars have gained their traction on the road and in the minds of the public via their rear wheels. For the last few decades, however, these vehicles seemed to be a dying breed.

With front-wheel-drive becoming the favoured method of transmitting power to the road, and four-wheel-drive and AWD also gaining in popularity, there were fewer examples of rear-wheel-drive vehicles in the market, and even fewer at the lower ends of the echelon.

While premium automakers such as Mercedes-Benz and BMW never left rear-wheel-drive behind, when DaimlerChrysler introduced the 300C in 2003, it was the first new rear-wheel-drive car from the company in more than a decade. And that is only one company.

While the debates over fuel economy versus performance and safety over style will no doubt persist, there is no arguing the increased importance that rear-wheel drive has seen among automakers.

Take Ford for example. The company that once threatened to replace its perennially successful Mustang with the front-wheel-drive Probe, has not only persisted with rear-wheel drive, it has reached back in time to give some classic muscle car styling to its new Mustang. And, lest we forget the halo car of all halo cars, there’s the Ford GT, which brings back the excitement of the Ford GT 40 that took on the world in sports car racing four decades ago and came out on top.

Over at Chrysler, the Dodge Magnum and 300C reach back a little further into the past for 1950s type styling with a little comic book excess. The 300C is a car Dick Tracy would be proud to be seen in.

Even GM has added a stablemate to its existing rear-drive offering with the GTO, which revives a 1960s moniker and high-performance, muscle-car image, if not its styling cues.

So, what does any of this mean to the automotive aftermarket?

Ron Strain, chassis program manager, Affinia Brake & Chassis, says that unexciting as it may sound, the change will probably be gradual and that suppliers such as Affinia will add applications to accommodate them as a matter of course.

“The general consensus is that as it affects steering and suspension parts, nobody seems to anticipate that there is going to be a real shift in demand on any particular components either way.”

This isn’t to say that the shift has gone unnoticed, but that regardless of how the shift goes, Strain expects the aftermarket to respond.

“I don’t think there is going to be a huge impact on our sales or anything. As long as the population is buying vehicles, we are delighted. Eventually they become the aftermarket’s customers. I don’t know if it makes that much difference as to the shift.”

The way that these and all new vehicles will find their way into the aftermarket, gradually filtering in over time rather than in one big inundation, is part of the reason for this view.

“It seems to be so gradual. Certainly this is the case over the last 10 years that the light truck market has begun to develop.

“Light truck popularity is a huge percentage relative to what it was 10 years ago. But when you spread that out over the decade, it has become business as usual.”

With the influx of new vehicles with old names–Mustang, 300C, GTO–one might be tempted to view them as old-fashioned. This would be a mistake.

Apart from their nostalgia-evoking names, the new generation of rear-wheel-drive cars is every inch modern, sophisticated vehicles.

Even a cursory examination might not reveal the level of sophistication. The new Mustang, for example, features a chassis system with MacPherson struts and a three-link live axle with Panhard rod. But that Panhard rod is tubular, and even the driveshaft is aluminum, on the V8-equipped models.

Look deeper still, and you’ll find that Mustang’s 300 horsepower MOD V8–a member of Ford’s modular engine family–weighs 34 kilograms less than a comparable cast-iron design and generates 40 hp more than the 2004 engine, more than 50% more ponies than the designers could whip out of the 1964 Mustang’s 289 V8.

Electronic throttle control, faster engine management controls and new three-valve cylinder heads with variable camshaft timing all contribute to this impressive output.

The three-valve heads with VCT allowed engine designers to use a higher compression ratio with regular 87-octane gasoline. Intake runners with active charge motion control valves also shape each combustion event for strong, low-end torque and maximum high-rpm power. Compare that to the drivetrain of yore.

Laurie Schlamp, president, Autotrans Inc., Edmonton, Alta., says that he expects that the introduction of high performance vehicles that are relatively affordable will have a multi-faceted affect.

“I think it will be good for the performance side of the business,” says Schlamp. Autotrans is a remanufacturer of transmission components as well as a supplier of transmission diagnostic equipment. It also has a substantial performance business.

“We do sell a fair amount of product for a front-wheel-drive performance, but the mainstay is still rear-wheel drive.

“From a regular maintenance point of view, I’m not really sure what kind of impact it might have,” says Schlamp. He does say, however, that the packaging of popular drivetrains with transmissions will drive transmissions that were previously considered low-volume units up the popularity list.

He offers the Mercedes 7226 five-speed automatic as an example. With the introduction of the Chrysler 300C, which is equipped with the transmission, it is inevitable that it will become more plentiful.

This he says means more models and more training, “but that is an ongoing situation.”

Schlamp muses that the biggest impact may not just come from the wear and tear that drivers will put on these vehicles. He believes that the emotional attachment that these cars will evoke in their owners will translate into business.

“I think that when people love a vehicle, that drives the market, either from just repair from the number of vehicles sold, or from the tuning side. From the [cars] that we are seeing the excitement about, they are for the most part rear-wheel-drive. I think that will certainly have an impact on the market size.

“Conversely, what will happen with higher fuel costs and the SUV? Are we going to see those slide back?

“I guess if we knew all the answers we would all make a lot of money as consultants.

“In the aftermarket we are always riding the wave. We are not going to determine what cars are going to be successful; we just have to respond accordingly.”

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Taming the Horses with Technology

One of the key advances that may very well have led to a resurgence in the rear-wheel-drive, high performance car is increasing accessibility to active safety technology.

While it would be pure speculation to suggest that automakers might be concerned about the potential risks to their legal bills if they put high-performance vehicles in the hands of too many ham-fisted members of the public, saving a driver from his or her own zeal has become commonplace.

While the Mustang does not have the most sophisticated system for doing this, it does have an optional four-channel anti-lock braking system, for a greater degree of brake control with traction control capability. It uses electronic sensors to constantly monitor road conditions and feed the information to a dedicated control computer which is capable of determining, within milliseconds, whether the vehicle is on dry pavement or negotiating a slippery surface. When traction control isn’t desired–like when a smoky burnout at the drag strip is in order–drivers can deactivate the system.

Electronic Stability Program (ESP), a name that has been used as a catchall for sophisticated systems that do more than just help a driver stop–activating single wheel braking based on inputs from steering angle sensors, for example–has come front and centre among active safety technologies.

ESP pioneer Robert Bosch has said that General Motors, Ford and Chrysler announced their intention to equip the majority of their SUVs with ESP as standard either immediately or starting in the next two years, and that the overall use of ESP is expected to double.

ESP recognizes unintended rotating movements of the vehicle at a very early stage. By reducing the engine output and braking wheels separately, the system counteracts skidding and keeps the vehicle safely on the intended track.

A study by the US National Highway Traffic Safety Administration (NHTSA) confirms the effectiveness of ESP. It found that the number of single vehicle accidents was reduced by an average of 35% in those passenger cars in the U.S. which had been fitted with ESP as standard between 1997 and 2002, in comparison to the same car models dating from the time before ESP was launched. The number of fatal road accidents decreased by 30%.

Similar results were published last October in a study by the Insurance Institute for Highway Safety (IIHS). The study found that the number of accidents in cars with ESP was 41% less than in the reference group. As regards fatal road accidents, the IIHS statistics indicate a decline of 56%.