But respond they did, with six-cylinder power first appearing in a U.S. 3 Series car in the 1985 325e. Still, the 2.5-liter engine, dubbed "eta" after the Greek letter meaning efficiency, was designed for low-end torque and high fuel economy. The eta was a good powerplant, but it wasn't exactly what everyone wanted, producing just 121 bhp at 4250 rpm although torque was 170 lb-ft at only 3250 rpm. In answer, BMW put a real engine in the 1987 325i, which revved to a full 6450 rpm and cranked out 168 bhp at 5800 rpm and 164 lb-ft torque at 4300 rpm. Top speeds for the 325e and 325i were 130 mph and 143 mph, respectively, according to the BMW Buyer's Guide by Fred Larimer. A convertible 325i also appeared in 1987, with production extending into 1992 for the U.S. market.
BMW tried reincarnating the venerable 2002, still golden in the hearts of enthusiasts, with a 318is model in 1990 and 1991, using the new dohc 1.8-liter four-cylinder engine dubbed the M42. A big step above the old four-cylinder powerplants, the M42 featured 10.5:1 compression, stainless-steel tube headers, hydraulic lifters and a massively overbuilt bottom end. The two-door 318is had black trim and was only available with a five-speed manual gearbox and a low 4.10 differential. It shared shocks with the E30 M3, and in fact quickly became known as the "poor man's M3." I put about 150,000 miles on one and can attest to its bulletproof nature. The only problem was a lack of torque, only partially made up for by the low gearing. The M42 engine produced 134 bhp at 6000 rpm and 127 lb-ft torque at 4600 rpm, and a top speed of 120 mph. But weighing in at just 2,602 pounds, handling and braking were its forte. Four-door and convertible versions were produced with an optional slushbox. The convertibles used a 4.27 differential, which is a popular upgrade for the 318is.
From 1988 through 1991 the first all-wheel drive Bimmer was imported to the U.S. market. The 325iX, priced over $34,000 in 1988, was not a sales success outside of New England and the upper tier states. The 325iX used the same gearbox and engine as the 325i, combined with variable demand-sensitive torque distribution by means of automatic viscous couplings in a transfer case and rear differential, along with a front differential. This yielded full time all-wheel drive without any action on the driver's part. Under normal conditions the torque split was 37% front and 63% rear. The front suspension was beefed up to prevent torque steer. The 325iX has a cult-like following today.
The markedly higher ride height of the 325iX signified BMW's persistent belief that all-wheel drive is a winter driving aid suitable mainly for harsh climates and road conditions, while rear-wheel drive provides signature BMW handling. The marketplace has decreed this view, however correct it may be, decidedly out of favor today. It's destined for change when the current 3 and 5 Series all-wheel drive models debut.
E36, 1992-1998: 318i, 318is, 323i, 323is, 325i, 325is, 328i, 328isThe E36's introduction in late 1991 signaled the end of the traditional box-type Bimmer and the beginning of the new swoopy aerodynamic designs. Following the trend established by the E30, the new 3 Series was bigger, heavier and more expensive than the one it replaced. The modern design was well received in all but the most traditional BMW circles, and even the "grapefruit must be eaten in halves and only in the morning" crowd eventually warmed to the E36. Underneath, the familiar MacPherson struts and wishbone control arms made up the front suspension, but there were big changes at the rear. The complicated but effective Z-axle multi-link rear suspension originally seen on the Z1 appeared in place of BMW's venerable semi-trailing arm design.
The E36 3 Series is reliable, moreso than most other cars. However, it had problems that didn't affect the E30. For all its good qualities, by many accounts the E36 has proven to be the least durable and the least reliable of all the 3 Series body styles. One may attribute this to the fact that the E36 represents BMW's first foray into the electronics explosion and computer-aided design (CAD) processes.
The 1992 318i had the M42B18 dohc four-cylinder engine, which was internally identical to the engine in the E30 1991 318is, but with a different intake system and the addition of knock sensors. It was rated at 138 bhp at 6000 rpm and 129 lb-ft at 4500 rpm.
The big news was the introduction of the M50 family of dohc six-cylinder engines. Carried in from the 1991 and 1992 525i, the original M50 was the M50B25. It was known for being very robust, with double valve springs, strong valves, beefy connecting rods and camshafts so hot that a little rumptiness at idle was not uncommon.
The 1993 model year saw significant changes in the 325i engine. The M50TUB25 (TU stands for Technical Update) included BMW's variable intake valve timing system, known as VANOS. VANOS is from the German "VAriable NOckenwellen Steuerung" (or Variable Camshaft Control). The system uses an ingenious electro-hydraulic two-position piston in conjunction with an internal/external helical gear on the intake camshaft secondary gear drive to vary camshaft timing according to engine load.
Topless motoring was reintroduced to U.S. BMW enthusiasts for the first time in two years, since the demise of the 1992 E30 convertibles. In comparison, the E36 chassis afforded a more rigid platform for a convertible, and that meant less cowl shake than was the case with the E30 ragtop.
BMW completely revamped the engines for 1996, out of mandatory compliance with the government's OBD-II regulations. The 318i received the M44B19, which was a mildly stroked 1.9-liter version of its previous engine. The 325i was gone, replaced by the 2.8-liter 328i models. Its new engine, designated M50B28, retained single VANOS capabilities. Stroke grew from 75mm to 84mm, now equaling bore. The resulting 18 lb-ft torque increase shaved a full second off zero to 60 mph times according to the elite automotive press, even though the rear differential shrank to 2.93 from the previous 3.15.
The big news for 1998 was the end of the four-cylinder engine in North America. Frustrated by the slow sales of automatic transmission models, BMW NA laid down the law: The cars had to be quick even with automatics. The 323i was powered by a 2.5-liter engine yielding 168 bhp at 5500 rpm and 181 lb-ft torque at 3950 rpm.