E12 Five Series

Background

The E12 five series appeared in 1972 . It replaced the highly acclaimed "Neu Klasse" four door saloons such as the 2000tilux and 2000tii, the cars which had saved the company from financial disaster in the sixties. The Neu Klasse set standards that completely outclassed the competition, so did the E12.

At the time BMW was having incredible success with the 1602-2002 series of small sports saloons and was doing well with the big 2500/3.0 luxury saloons. The new five series was somewhere in the middle and was the first post-war BMW to use the now familiar three digit naming system. It used the same layout pioneered in the Neu Klasse saloons but with more modern packaging and styling. The later E28 looked extremely similar and wasn't discontinued until 1988!

Models

All E12s were saloons. The special 1980-81 M535i was the Motorsport divisions first saloon car and was a very hot beastie for its day, the first of a long line of super saloons.

All the four cylinder cars had rear drum brakes, the sixes had disc brakes. The braking system on the car is based heavily on that of the 2002.

US customers received the 530i initially. In order to pass EPA rules the car had the now infamous thermal reactor anti-pollution system. Economy was abysmal and thermal problems caused many cracked cylinder heads. These cars are to be avoided in favour of the US 528i or a euro-import.

BMW E12 Alpina

Alpina showed what the E12 was capable of.

BMW E12 interior

BMW E12 M535i

E12 had luxurious interior.

1981 UK M535i

Engines

The first euro models were the 520 and 520i based on the faithful M10 four cylinder engine. A year later these were joined by the first Big Six M30 E12, the carb 525 with 150bhp. In 1974 the range was broadened with the introduction of the smaller 1.8 M10 which five years later was also available with injection.

The M10 was replaced by the new Little Six M20 in 1979.

The M535i used the drivetrain from the E24 635CSi in a car that weighed 100kg less. It also had such racing car features as a final drive oil cooler, dog-leg gearbox and Recarro interior. In 1980 this car caused quite a stir. The little known 533i Motorsport was effectively a dry run for the M535i in 1978, very few were made and they are now ultra rare.

Model Body styles Engine Produced
between
Weight
(kg)
Power / Weight
(bhp / 1000kg)
Final drive ratio
(manual / auto)
Brakes
518 Saloon M10 1974-81 1110? 81? 4.44 until 9/79 then 4.27 Disc/Drum
518i Saloon M10 1979-81 1130? 90? 4.27 Disc/Drum
520 early Saloon M10 1972-79 1120? 97? 4.10 Disc/Drum
520 late Saloon M20 1979-81 1220? 100? 3.91 Disc/Drum
520i Saloon M10 1972-79 1130? 110? 3.91 Disc/Drum
525 Saloon M30 1973-81 1310? 114? 3.64 Disc/Disc
528 Saloon M30 1974-77 1310? 126? 3.64 Disc/Disc
528i Saloon M30 1977-81 1310? 140? 3.45 Disc/Disc
533i Motorsport Saloon M30 1978 1340? 154? ? LSD Disc/Disc
M535i Saloon M30 1980-81 1360 160 3.07 LSD with oil cooler Disc/Disc
US 528i Saloon M30 1978-81 1380? 122? 3.45 Disc/Disc
US 530i Saloon M30 1974-78 1380? 127? 3.64 until 7/76 then 3.45 Disc/Disc

 

See the engine details page for power figures. US power figures for this car were quite a bit lower than euro figures and the cars were a little heavier. In addition the smaller engined models were never available in the US.

The M535i and maybe some other models had the dog leg close ratio gearbox with first gear on it's own and second, third paired next to fourth and fifth.

Known Problems

For the early 520 / 520i see M10 engine problems.

For the later 520 / 520i see M20 engine problems.

For the others see M30 engine problems.

US 530i models had the notorious anti-pollution thermal reactors. These gave a terrible 12-15mpg and caused cracked cylinder heads.

ZF HP 22 automatic transmissions can fail if revved strongly whilst in neutral or park.

The vacuum assist on the brakes can fail, especially on RHD cars. It's very similar to that on the 2002.

Carefully check fuel lines and tank for corrosion, especially where the filler pipe meets the fuel tank.

Heating can stick fully on or off due to faulty heater control valve, not that expensive to fix.

Rear differential mounts were weak and must be checked. The M535i's was stronger.