BMW 5 E12

The first 5 Series wasn't really much smaller than the "big" E21 model sold alongside it. With a 103.8-inch wheelbase and 181.9-inch overall length, the 1972 520 was a significant 4.7 inches longer than the 2000 sedan it replaced (and only 3.1 inches less lengthy than the European-model 3.0S version of their large sedan). Considering that the only engine offered in the 5 Series during that first year of production, a 2.0-liter four making 115 hp breathing through a carburetor in the 520 or 125 hp when ingesting atmosphere through a fuel-injection system in the 520i, the first 5 was underpowered. And, wisely, BMW concluded it wasn't an appropriate vehicle to market in America in that form.
The basic elements of the first 5 Series weren't exotic. As in the New Class, the front suspension was a pair of simple MacPherson struts while the independent rear was supported by a set of semi-trailing arms. The unibody structure was impressively taut, the four-wheel disc brakes were effective and it was probably the quietest and most refined BMW that had yet been built.
But the first 5 Series still carried with it a slew of innovations for BMW. For starters, it was the first vehicle to use the present-day naming scheme (series number followed by two numbers indicating engine displacement). Second, it was the first BMW designed to accommodate any of the company's four- or six-cylinder engines (the first six-cylinder 5, the 2.5-liter 525, appeared in Europe for the 1973 model year). Third, it was a simpler and cheaper car to build than other BMWs, and that made it tremendously profitable. Fourth, despite its economical construction, it was a leap forward in refinement and sophistication. And fifth, it was a much more contemporary design than previous BMW sedans, which was an enormous help in shedding the company's heretofore dowdy image through the '70s.
BMW finally brought the 5 Series to America for the 1975 model year when the 3.0Si's SOHC, 3.0-liter, straight six was installed to produce the 530i. The 530i was designed for America, and the big engine was particularly needed over here because of the then-new emissions regulations that were strangling engine outputs (the '75 model year was the first in which most new cars were equipped with catalytic converters - though the 530i itself managed to get by without one). By mid-1970s standards, the 530i's 176 hp was startling for a 3.0-liter engine - that same year the Cadillac Eldorado's 8.2-liter V8 was rated at just 190 hp and the most powerful 5.7-liter V8 offered in the Chevrolet Camaro made just 155 horses.
Beyond its exemplary output, the 530i's six was silken and delivered its torque in an elegant, unbroken ribbon, and the Getrag four-speed manual transmission behind it was nearly as sweet (the optional three-speed automatic wasn't so enchanting). With so many other new cars then out there gagging on their emissions gear, wallowing on Conestoga-era suspension and wearing garish vinyl roofs and opera windows, the 530i was a paragon of performance, composure and good taste. Road & Track spurred one 530i to 60 mph in 10.2 seconds and Motor Trend measured one doing the same trick in 9.7 seconds. That's performance pretty close to the European market's 528 model that used a 2.8-liter version of the straight six but didn't carry America's oversize bumpers and emissions equipment. It was all enough to make the car's $9,097 base price seem absolutely reasonable.
The 530i was an instant hit, and consequently, BMW didn't mess with it for 1976. A slight restyling came with the 1977 model year that made the front grille's distinctive twin kidney center taller and more prominent leading to a new narrow raised center along the hood. The taillights were also redesigned and made larger. Those changes were enough to carry the car through 1978 as well.
BMW brought the 2.8-liter inline six over to America's 5 Series as a replacement for the 3.0-liter to create the 1979 528i for the American market. While BMW rated the 2.8-liter motor at 169 hp, the use of a catalytic converter, other new emissions technologies and a new five-speed manual transmission actually improved drivability, fuel economy and performance. Road & Track even got one 528i to 60 mph in just 8.2 seconds.
Though it never came to the United States, BMW produced one of the most significant 5 Series models ever during '79. The M535i was the first product of the BMW Motorsport division to reach consumers and featured a large-bore/short-stroke version of straight six displacing 3.5 liters and making 218 hp. Available only in Europe and only backed by a close-coupled five-speed manual transmission, the M535i was the prototype for all the glorious M cars to follow - M1, M3, M5 and M6. It's also easily the most desirable of all the original E12 5 Series cars.
There were few changes to the 1980 528i and even fewer for 1981. But it was time for the 5 to evolve.