For 1990, the versatile Mercedes-Benz 300-class formed the backbone of automaker's midsize lineup. Trim packages included a 300CE coupe with a new single-cam 3.0-liter, 6-cylinder engine that pumped out a peppy 217 hp, and a 300SL convertible with a 3.0-liter, 228-hp engine. Other models, including the 300E, SE, and SEL sedans, and the 300SL and the 300TE wagon, came with a 177-hp 3.0-liter single-cam engine. A 4-speed automatic transmission was standard across all models of the 300-class, as was a new fuel-injection system, anti-lock brakes, and airbags for the driver and passenger. Power windows, power door locks, air conditioning, and a cassette player were also standard for all models. Options included a five-speed automatic overdrive and a sunroof (except for the SL convertible model, of course). Leather seats were standard on the 300E, SE, SEL, and E 4MATIC sedans, on the SL convertible, and on the CE Coupe. They were available as an option on the other models.