Both technologically and stylistically, the 1966 Oldsmobile Toronado was a landmark — a striking, sophisticated big GT that was also the first front-wheel-drive American production car in nearly 30 years. This week, we look at the origins of the 1966-1970 Toronado and the evolution and development of its unusual FWD Unitized Power Package.
Today, front-wheel drive is ubiquitous, found on everything from tiny Japanese kei-cars to crossover SUVs. Until the early eighties, however, the majority of passenger cars in America, Europe, and Japan used le Système Panhard: a front-mounted engine driving the rear wheels through a central propeller shaft. The “FR” layout had its drawbacks, but it was simple, durable, and, more importantly, cheap. Various alternative layouts had been essayed since the earliest days of the automobile — Walter Christie built a number of successful FWD race cars as early as 1904 — but for various reasons, they failed to unseat the well-established incumbent.
Although mid-engine, rear-drive (MR) configurations came into vogue for sports cars in the seventies, the major rivals to the FR setup were the rear-engine, rear-drive (RR) and front-engine, front-wheel-drive (FF) layouts. Both the FF and RR formats offer several advantages over the FR layout. The first was superior traction, a result of putting the mass of the engine directly over the drive wheels. The second — especially compelling for smaller cars — was packaging efficiency. In an FR vehicle, the occupants must share space with the propeller shaft and differential, which are particularly intrusive in low-slung cars like the first four-seat Ford Thunderbird. Packaging the entire drivetrain at one end of the vehicle leaves more room for passengers and cargo, and it can also facilitate assembly, allowing the powertrain to be installed as a single unit.
Both configurations also have notable drawbacks. RR cars are more practical with air cooling than with water cooling, and their inherent tail-heaviness reduces their straight-line stability and encourages some unwelcome cornering behavior. FF cars, by contrast, tend to be quite stable, but their front weight bias produces heavier steering; making the front wheels responsible for both power and steering also causes its own handling quirks. Front-wheel drive also tends to be expensive, in part because of the multiple universal joints or constant velocity joints needed to allow the driveshafts to accommodate the full range of wheel motion.
Except for the unique V-8-powered Tatra, the RR layout tended to be associated with small economy cars, but before World War II, front-wheel drive had a much racier image. The lack of a propeller shaft allowed FWD cars (particularly single-seat race cars) to be lower with a smaller frontal area and a lower center of gravity, both very beneficial on the track. Engineer Harry Miller offered a number of quite successful front-drive race cars in the late twenties, which led to a brief vogue for FWD prestige cars like the Cord L-29, the short-lived Gardner and Ruxton, and a stillborn V-12 Packard. While the subsequent Citroën Traction Avant and Cord 810/812 were not quite luxury cars, they were definitely upscale in both price and appointments. Unfortunately, most of those cars suffered significant teething problems, and the Depression was not an opportune time for launching new models with expensive new technology. Only Citroën’s Traction Avant survived the decade.
When automotive production resumed after the war, European manufacturers developed a new generation of inexpensive FF cars, including the Citroën 2CV, Panhard Dyna, Saab 92, and Borgward Goliath. In America, however, front-wheel drive was all but extinct. Henry Kaiser‘s plans for a postwar FWD car never made it past the prototype stage, and even early domestic compacts like the Nash Rambler and Hudson Jet had conventional FR layouts. The last American production car with front-wheel drive had been the Cord 812, which was discontinued in 1937.
Still, the advantages of the FF configuration were not lost on Big Three engineers. In 1955, GM exhibited a number of FWD concept cars at its traveling Motorama show: a roadster and a four-door hardtop christened LaSalle II and a compact panel truck called L’Universelle.
Conceived by GM Styling and the corporate Engineering Staff, the LaSalle II cars were intended to showcase various advanced features, including front-wheel drive, unitized construction, fully independent suspension, and a transversely mounted fuel-injected DOHC V-6. The FWD powertrain, developed by the corporate Power Development and Transmission Development Groups, was called the “Unitized Power Package,” or UPP, combining engine and transaxle into one compact unit. We’ve been unable to find detailed specifications for the LaSalle II’s UPP, but in any case, it appears they were largely notional — the show cars didn’t run, and their mock-up powertrains were rear-wheel-drive. The Engineering Staff didn’t actually complete a functional UPP prototype until sometime after the Motorama closed.
The GMC L’Universelle was slightly more realistic, mating Pontiac’s new 287 cu. in. (4,706 cc) V-8 to a three-speed transaxle based on the four-speed Dual Range Hydra-Matic. Like the the Citroën Traction Avant and DS-19 (which bowed around the same time), L’Universelle had a longitudinal engine, rotated 180 degrees and mounted behind the transaxle; the differential gears reversed the transmission’s rotation so the van wouldn’t move backward in Drive. Front suspension was by double wishbones and longitudinal torsion bars (adopted to allow the halfshafts to pass between the wishbones) while the rear used a dead axle with a dropped center section that allowed the van’s interior to have a deep, flat load floor.
In many respects, L’Universelle was very practical, offering maximum utility space in a relatively compact package, but the awkward cooling system layout — with a roof-mounted grille passing air to a radiator mounted behind the front seats — suggested that the van wasn’t quite ready for prime time. Nonetheless, GMC did seriously consider putting it into limited production for 1956, now with a transversely mounted 317 cu. in. (5,188 cc) Pontiac engine, dual-coupling four-speed Hydra-Matic, and a bus-derived angle drive system. High costs and the project’s likely very high price tag finally led GMC to pull the plug in 1956.
THE FRONT-DRIVE F-85
There was also interest in front-wheel drive at some of the divisions, which in those days still did much of their own research and development work. Toward the beginning of 1957, Oldsmobile advanced engineering chief Andrew K. Watt embarked on a new project to develop an experimental FF powertrain.
As an Advanced Design Group project, this was not initially tied to any specific production program, but later that year, the worsening “Eisenhower recession” prompted GM to launch the new X-100 program, aimed at giving each of the corporation’s mid-price divisions a compact car to sell. The result would be the introduction for 1961 of GM’s “senior compacts”: the Buick Special, Pontiac Tempest, and Oldsmobile F-85. Watt and Oldsmobile assistant chief engineer John Beltz thought the F-85 would be an ideal application for front-wheel drive, allowing greater interior space despite the smaller external dimensions. The senior compacts were already slated to have all-new engines and transmissions, so it seemed like a perfect time to try something new.
In early 1958, Watt’s group began feasibility studies for a FWD compact, initially using a static test fixture to test a prototype powered by an all-new, Oldsmobile-designed 60-degree aluminum V-6 displacing about 215 cu. in. (3.5 L). A short front subframe carried the engine, transmission (a four-speed Hydra-Matic), and differential. The engine and transmission were both mounted transversely, but the transmission sat behind the engine and was driven from the flywheel by a short length of chain. A second chain drive connected the transmission output shaft to the differential. Oldsmobile also explored gear drive and cogged belt drive as means of transferring power from the engine to the transmission, but eventually concluded that belt drive would present durability issues, while gear drive was too costly and too noisy.
At Oldsmobile’s request, the Engineering Staff also did additional development work on chain drives. The engine of the early Engineering Staff prototype had an extended crankshaft to accommodate a chain drive between the engine and the torque converter, with the transmission (initially a two-speed automatic similar to the Buick Dual-Path Turbine Drive, later a three-speed automatic of a type not otherwise used by GM production cars) mounted alongside the engine and a bevel gear differential behind it. The initial prototype racked up about 6,000 miles (9,600 kilometers) in road testing. The Engineering Staff also created two test setups for durability testing of the chain drive.
In early 1960, Oldsmobile cobbled together its first running prototype, the A20A. Different sources variously describe the A20A as being based on a 1959 Rambler Six, a Chevrolet Corvair, or a preproduction Oldsmobile F-85. In any event, the prototype shared the F-85’s 112-inch (2,845mm) wheelbase and the new 215 cu. in. (3,528 cc) “Rockette” V-8 (the Oldsmobile version of the all-aluminum Buick engine), but was shorter overall, with a length of only 180 inches (4,572 mm), and more than 400 lb (180 kg) heavier, tipping the scales at a hefty 3,363 lb (1,526 kg). Its driveshafts initially used a combination of Rzeppa-type constant velocity (CV) joints and telescoping universal joints, later changed to inner and outer CV joints. Proving grounds testing was promising, demonstrating satisfactory handling and excellent stability.
By the time these tests were underway, any thought of using FWD in the compact F-85 had obviously been tabled, or at least postponed. The initial Y-body F-85 was already in or close to pilot production by then, with a conventional FR layout, although it appears Oldsmobile was still considering FWD for future compact models, perhaps the second-generation F-85.
If that was the plan, it changed considerably by mid-1961. The 1961 model year had not been a strong one in general, and early sales of the Oldsmobile F-85 were disappointing, leaving Oldsmobile wondering if the entire senior compact project had been a mistake. The F-85 was pricey for an economy car, in part because its aluminum engine was expensive to produce; a FWD version would be even costlier. More profitable dress-up models like the sporty Cutlass, launched in May 1961, seemed a safer bet for the compact market, particularly since the sales triumph of the Ford Falcon over the Corvair suggested that economy car buyers had little appetite for technical novelty.
Oldsmobile was not ready to abandon the idea of front-wheel drive, but by the summer of 1961, Beltz and Watt had shifted their focused to full-size cars; Oldsmobile’s third FWD prototype was a converted Dynamic Eighty-Eight.
Oldsmobile chief engineer Harold Metzel and division general manager Jack Wolfram pitched the idea of a full-size FWD model to corporate management, but met with considerable resistance and no small amount of skepticism. A FWD compact was one thing, but a full-size car with a torquey modern V-8 was something else, and some senior corporate executives doubted it would work. It was clear that selling a big FWD Oldsmobile to the corporation would be an uphill battle.