Original vintage late 1980s BMW 3-Series 325e sports sedan advertisement, "BMW Puts 6 Cylinders Where 6 Cylinders Have Never Been Before."
Dimensions: 7.75 inches wide by 10.75 inches high.
The BMW E30 is the second generation of BMW 3 Series, which was produced from 1982 to 1994 and replaced the E21 3 Series. Externally, the E30's appearance is very similar to twin headlight versions of its E21 predecessor, however there are various detail changes in styling to the E30. Major differences to the E21 include the interior and a revised suspension, the latter to reduce the oversteer for which the E21 was criticized.
The BMW 325e, part of the E30 generation, is known for its smooth, torquey engine and comfortable ride, but it's also criticized for being less sporty than other E30 models and having a somewhat underpowered feel at higher RPMs. It's a great choice for those prioritizing a relaxed, comfortable driving experience with good fuel economy, but it may not satisfy enthusiasts seeking a more engaging or powerful driving feel.
BMW’s E30 325e was a stop-gap measure in the U.S. market. The E21 had been available with a six-cylinder engine in Europe, but the E30 325e was the first six-cylinder-powered 3 Series sold in the U.S.; the E21 it replaced had been available solely with a four-cylinder, first in two-liter displacement, and then with the 1.8-liter M10B18 engine.
May 1982 marked the start of U.S.-market E30 production with the M10-powered 318i, long viewed as the underdog of the U.S. model range. Production of the U.S. 325e started in July 1983, after the 318i had already been around for a while, familiarizing the public with the E30 shape.
The M20B27, according to BMW brochures and other ephemera from when they were new, explains that the engine was designed with efficiency in mind. Although the redline arrived early, at just 4,800 rpm (or as low as 4,750, depending on your source), for non-super-eta engines, additional revs weren’t needed, as significant torque—170 pound-feet for U.S. cars (not much less than the S14B23 of the E30 M3)—arrived at 3,250 rpm.
The e is an abbreviation for eta, which is used to represent the thermal efficiency of a heat engine. To maximize low-rev torque, the 325e engine was the largest available in an E30 (aside from the 333i model, which was only sold in South Africa). The 325e engine had a longer stroke than the 325i version, with a more restrictive head, four cam bearings instead of seven, and single valve springs (instead of the dual valve springs used by the 325i version).