The E32: making the engine serve the car
BMW’s production V12 emerged from a fresh development program begun in late 1982, after earlier experiments had failed to justify themselves. By the time the car reached Geneva in March 1987, the company reported more than 3,000 advance orders. It was an encouraging reception for a manufacturer asking buyers to reconsider where its sedan range ended.
The M70 displaced 4,988 cc, with its cylinder banks set at 60 degrees. Its 84 mm bore and 75 mm stroke matched the contemporary 2.5-liter BMW six, but the new engine was not two complete sixes joined together. The aluminum silicon block, chain driven camshafts, hydraulic valve adjustment, and electronic throttles made it a distinct production design. Each head carried one camshaft and two valves per cylinder. Maximum breathing at extreme engine speeds was not the priority; compactness, smooth running, and useful torque were.
In this layout, each bank has the favorable reciprocating balance of an inline six. Across the engine, a combustion event occurs every 60 degrees of crankshaft rotation. That closely spaced delivery reduces the gaps between pushes on the crankshaft. It does not abolish torsional vibration, accessory noise, or the need for good mounts, but it gives the engineers unusually agreeable material to work with.
A coin standing on an idling engine was an excellent advertisement because it made an ordinarily invisible quality comprehensible. Yet the production achievement extended beyond the absence of shaking. Intake noise, injector ticking, exhaust pulses, and vibration transmitted through the mounts all had to be kept from the cabin. The M70 could not merely be smooth on a stand. It had to remain unobtrusive while coupled to a transmission, an exhaust system, and a body full of resonant surfaces.
The controls are often described as aircraft style redundancy. The reality is more interesting and less absolute. Each bank had its own Bosch Motronic controller, airflow measurement, throttle body, ignition coil, and distributor. A separate EML controller coordinated the electronic throttles. The arrangement permitted limited operation after certain faults on one side; it did not create two entirely independent engines. Cooling, lubrication, the crankshaft, electrical supply, and parts of the control strategy remained common dependencies.
Duplicating the bank controls also allowed BMW and Bosch to use established control hardware. The result was an elegant bridge between the capabilities of available electronics and the needs of a new engine. Electronic throttles allowed torque to be managed without relying solely on the driver’s right foot. Cruise control, idle regulation, and traction management could ask for a change, and the engine could deliver it through the same actuators.
The European rating was 300 PS, equivalent to approximately 296 hp, with 450 Nm, or 332 lb-ft, of torque. The modest 8.8:1 compression ratio and two valve heads reflected an engine intended to deliver its performance without extreme operating conditions. BMW had not used 12 cylinders to create a peaky 5.0-liter engine. It had used them to make a useful one unusually agreeable.
The sedan around the engine
The E23 had already offered a substantial BMW sedan, including the turbocharged 745i in some markets. The E32 replaced its more upright proportions with a lower looking body and broader stance. In the 750iL, an additional 4.5 inches of wheelbase went to the rear passenger compartment. That extension was important: the car could retain BMW’s driver oriented layout without treating passengers as an afterthought.
The chassis combined front struts with semi-trailing rear arms and, on the 750iL, hydraulic rear self-leveling. The leveling system countered the change in ride height caused by passengers and luggage; it did not turn the rear suspension into an air spring system. A four speed automatic kept the power delivery continuous enough for the engine’s purpose. Neither component was the newest imaginable solution in isolation. Their calibration mattered more than the catalog description.
The original Car and Driver test nevertheless criticized the steering and noisy climate control. Those complaints belong beside the excellent performance figures. Speed dependent assistance can alter steering effort without improving the information reaching the driver, and a quiet engine is little consolation when the ventilation insists on conducting the conversation. The E32’s sophistication did not exempt its individual systems from ordinary judgment.
Inside, BMW kept the angled dashboard and recognizable controls while adding climate regulation, powered adjustments, and communications equipment around them. Electronic damping and insulating glass expanded the E32’s capabilities during its production life, with availability dependent on date and market. The resulting car could be highly elaborate without looking like an experiment from the driver’s seat. This restraint in the interface would later prove harder for BMW to preserve than smoothness in the engine.
Highline equipment carried the passenger brief much further. The refrigerator and tables were not advances in propulsion, but they changed the way the car could be used. A buyer no longer had to choose the V12 BMW solely because he intended to drive it. The rear cabin could support the same preference. The added equipment also brought more wiring, plumbing, electrical demand, and mechanisms into a car already distinguished by its complexity. Luxury had acquired a substantial service manual.
Factory protection brought another kind of load. Armor requires more than inserting heavy panels: glazing, hinges, suspension, brakes, and the surrounding structure have to remain compatible with the added mass. The V12 supplied useful reserve for moving the result without making every additional pound evident at the accelerator.
Against the W126 560SEL, BMW had a convincing new combination rather than a monopoly on quality. The Mercedes offered a mature body, substantial V8 performance, and a carefully developed luxury car. Its age became a disadvantage when buyers valued the BMW’s particular mixture of refinement and newer controls. It did not make every Mercedes virtue disappear. The competition was difficult precisely because the incumbent was good.
The Bentley Turbo R complicated the picture in another direction. Its turbocharged V8, upright accommodation, and distinctive cabin were not attempts to reproduce the BMW. Buyers could reasonably prefer that experience while conceding the E32’s more contemporary integration. What BMW threatened was not Bentley’s right to exist. The E32 threatened the assumption that a much higher price automatically bought a more accomplished machine.
The 750iL’s speed brought it into conversations previously reserved for sports cars, but a top speed does not make a sedan a substitute for one. Braking repeatedly, changing direction, shedding heat, and communicating tire load present different demands. The BMW’s achievement was to carry four adults quickly without asking them to endorse every compromise that made the sports cars entertaining.
Goldfisch and the limits of more
Goldfisch tested how far the cylinder argument could be extended. BMW’s engineers built a 6.6-liter V16 and installed it in an E32 experimental car. Four extra cylinders lengthened an already substantial engine enough to displace the normal cooling installation. The radiators went to the rear, where conspicuous ducts fed them through the bodywork. The prototype is a wonderfully direct illustration of packaging debt: the engine gains four cylinders, and the trunk receives the bill.
There is a difference between demonstrating that such a car can run and demonstrating that customers should buy it. Cooling performance, luggage room, noise, crash structure, assembly, and service access would all have needed production answers. The ducts were not merely a styling eccentricity. They were a visible record of what the new engine had displaced.
BMW built a second Goldfisch in 1990, with a different body and a more integrated installation. The two prototypes record successive attempts to accommodate the larger engine rather than a single finished car. Their existence is more revealing than a speculative top speed: BMW was spending real engineering effort on the question of whether the luxury sedan needed another four cylinders.
Goldfisch exposed the limits of the original proposition. More cylinders might improve some sensations, but their value had to exceed the cost of everything required around them. The E32 V12 had found a commercially workable balance. The V16 made the trade much harder to defend.
A Mercedes W18 proposal approached the same packaging problem through additional banks rather than an even longer conventional V. Shortening the engine would complicate crankshaft design, induction, exhaust routing, and cooling. Both ideas reveal how quickly the pursuit of a larger number could multiply the surrounding work. Neither reached production.
Meeting the competition
The production car needed none of that mythology. It had taken a configuration associated with specialist machinery and made it an expensive but recognizable BMW purchase. A V12 badge was no longer confined to the exotic corner of the market. The sedan’s ordinary silhouette made the mechanical extravagance more, not less, provocative.
The result demonstrated that the E32’s combination could survive direct comparison with quite different cars, not merely a sympathetic launch drive. The Lexus also posed a question that would outlast the test: how much should a customer pay for quiet, careful assembly, and agreeable daily operation? A V12 badge could identify an expensive answer without proving it was the only good one.
Mercedes’ M120 supplied a formidable alternative. It displaced 6.0 liters, used four valves per cylinder and double overhead cams, and powered a larger new S-Class. The launch European ratings of 408 PS for the Mercedes and 300 PS for the BMW show a substantial difference without mixing horsepower standards. Mercedes had chosen more output and more surrounding car. The larger, more elaborate Mercedes engine gave the rivalry a substantial mechanical foundation.
The W140 offered room, isolation, and an extraordinary concentration of equipment. Its size was an advantage from some seats and an inconvenience from others. BMW’s less monumental sedan remained attractive to someone who wanted the car to feel manageable from behind the wheel. By then the E32 had accomplished its most important task: the argument was no longer whether BMW belonged in this comparison, but which kind of excellent large car the buyer preferred.
