- March 9 - 19: The 2.5 liter fuel injection 250 SL, produced since December 1966, is officially presented at the Geneva Motor Show as the successor to the 230 SL. A variant is also available fitted with an enlarged luggage compartment and rear seat bench rather than the roadster soft-top and soft-top compartment.
- April: Mercedes-Benz expands its domestic passenger car range with the addition of a 7/8-seater version of the 200 D (W 110) with lengthened wheelbase. Originally intended for export only, the variant is equipped with two folding seats in front of the rear seat bench for up to three people and is the first long-wheelbase Mercedes-Benz saloon in the intermediate class.
- May 9: The new test site for cars and commercial vehicles in Untertürkheim is unveiled. The test track, which includes a high-speed test section featuring a 90° horizontally sloping high-bank curve, has a total length of 15,460 m. Although in theory, this curve can be taken at 200 km/h, in practice 150 km/h is the limit, as the human body cannot withstand driving around curves at higher speeds. Other test areas featured at the site are the skid pan, torture track and artificial inclines of up to 70% gradient.
- August: All Mercedes-Benz car models are equipped with a new safety steering system as standard. It consists of a steering column which telescopes in a frontal collision and a steering wheel impact absorber which reduces the risk of injury upon impact with the steering wheel.
250SL (W 113 A): Same car but with 2.5 litre engine with 150 hp and 7 instead of 4 crankshaft bearings. Larger fuel tank. Four-wheel disc brakes. Series production from December 1966, introduced in March 1966. A 280SL production started late this year.
The 200D 7 seater saloon was introduced in May, Intended as a taxi or rental car, hotel, or airport-shuttle service, for group trips, etc.
280S (W 108): Differs from the preceding type 250 S by new engine with uniform cylinder spacing in the block (previously paired standing close to each other). Differs externally by lower and wider grille. Production from November 1967.
280SE (W 108): Same car with fuel injection engine. Production from November.
280SEL (W 108): The same car as the 280 SE, but wheelbase extended by 10 cm.
300SEL (W 109): The most advanced (and most expensive) of the range with longer body and air suspension now usesthe new 2.8-liter injection engine of the 280 SL instead of the more expensive to manufacture light-alloy unit. Production from December.