News

BMW 3 Series Engines Through the Years: From Carburetors to Twin-Turbochargers

It’s no secret that the BMW 3 Series is a routine favorite among automotive enthusiasts and journalists, and part of that appeal is always thanks to the supple, high-performance engines at the heart of any 3 Series. With 36 years of engine development under its belt, BMW offered us a brief look back at the history of the 3 Series powertrain. Note, though, that not all of the engine varieties mentioned were sold in the U.S. market. So brush off your notebooks, and read on for a lesson on 3 Series history.

While it would later stake its claim to a series of inline-sixes, the 3 Series began life in 1975 with a compact inline-four engine. Of the four launch versions — 316, 318, 320, and 320i — only the top model had fuel injection. Offering a healthy 125 hp, the 320i sedan was subsequently crowned “world’s best sedan” in Europe.

But what’s automotive history without the addition of more power? By 1977, BMW had developed a new pair of inline-six engines, the 320/6 and range-topping 323i. The latter packed electronic ignition and 143 hp, but both engines were praised for their flexibility, smooth running characteristics, and surprising fuel economy. An entry-level four-cylinder also joined the fray in the late 1970s, in the 75-hp BMW 315.

When the second-generation 3 Series arrived in Europe in 1982, the base 316 boasted 90 hp from a carbureted four-cylinder engine. The two inline-sixes continued, with the hot 323i proffering 139 hp thanks to electronic fuel injection. In 1984 BMW launched the “eta” six-cylinder, a version of the engine with torque and fuel-economy at the forefront of its design goals. The 2.7-liter inline-six produced 122 hp, returned up to 28 mpg, had a catalytic converter, and boasted fully digital engine management.

The first diesel engine for the 3 Series arrived in 1985: the 324d boasted 86 hp and could cover almost 34 miles on a single gallon of diesel. Much more exciting, though, was the debut of the BMW M3, the first in a long line of high-performance variants of BMW products. A 2.3-liter inline-four engine provided 200 hp and went on to power a series of successful Touring Car racers in European championships.

More Valves, VANOS, and Diesel for the 1990s

A new generation of the vaunted 3 Series bowed in 1990, bringing with it engine improvements like dual-overhead camshaft designs and four-valve cylinder heads. BMW also brought its VANOS technology the 3 Series, allowing variable valve timing to improve power and economy. The generation’s top-rung engine was the 328i with an inline-six good for 193 hp. Two new turbodiesel sixes debuted, the 2.5-liter, 115-hp 325td, followed by the 325tds with 143 hp — which ran from 0-to-60-mph in 10.4 seconds.

Later, BMW introduced direct injection on the fourth-generation 3 Series with the 320d, a four-cylinder diesel engine with performance credentials of 136 hp and a 128-mph top speed, yet economy of up to 41 mpg. For gasoline engines, BMW upgraded its valve-timing system to Double VANOS, allowing even better control of emissions and torque output. Among the applications was the new 330i, which packed a 3.0-liter inline-six good for 231 hp — more than the first BMW M3. BMW claims it “set the new benchmark” for flexibility, reliability, performance, and efficiency.

Similarly, the 330d diesel received a rash of technical advancements: multivalve heads, direct injection, and a variable-turbine turbocharger, all of which conspired to produce 184 hp and a top speed of 141 mph. Even with the performance, it still returned 35 mpg.

In 2001, BMW launched Valvetronic, a system that eliminates a traditional throttle body and instead varies the opening of individual intake valves. It continues to be used on the majority of BMW engines (including Mini engines) today.

The fifth-generation 3 Series launched with three gasoline engines and one diesel: 320i, 325i, 330i, and 320d. The diesel scored common-rail injection and a variable-geometry turbocharger, helping power climb to 163 hp; the 320i four-cylinder offered 150 hp. Thanks to the addition of Valvetronic, output of the 330i shot up to 258 hp, and that of the 325i rose to 218 hp; a new magnesium-aluminum crankcase helped trim weight from the inline-six engines. The next big step in 3 Series engine advancement came with the 335i coupe, launched in 2007. Its 3.0-liter, twin-turbocharged engine was rated at 306 hp, and quickly spread to other models in BMW’s lineup.

Engines for the current 3 Series range from the tiny 115-hp 316d diesel and 143-hp 318i, to the twin-turbo 335i and the 4.0-liter V-8 in the go-fast M3. BMW maintains that its entire engine lineup offer engaging performance, while returning impressive fuel economy and a flexible, reliable driving experience. For the ultimate in efficiency, the special 320d EfficientDynamics can provide up to 57 mpg in European testing.

Now, who’s ready for a pop quiz on BMW engines?

Source: BMW

Comments
We’ve Temporarily Removed Comments

As part of our ongoing efforts to make AutomobileMag.com better, faster, and easier for you to use, we’ve temporarily removed comments as well as the ability to comment. We’re testing and reviewing options to possibly bring comments back. As always, thanks for reading AutomobileMag.com.

Buying Guide
Powered by Motortrend
2011 BMW 3-Series

2011 BMW 3-Series

MSRP $46,450 328 i Convertible

EPA MPG:

18 City / 28 Hwy

Horse Power:

230 @ 6500

Torque:

200 @ 2750