Porsche introduced the base model 944 for the 1982 model year. At its launch, it featured a 2.5 liter four cylinder engine capable of producing 143 hp for US market vehicles. European versions were capable of 167 hp. In mid-1985, the 944 underwent its first significant changes which included a number of interior features and suspension improvements. For the 1987 model year, the 944 Motronic DME was updated, and newly incorporated elements included anti-lock braking system and airbags. In early 1989 Porsche upgraded the base model 944 engine from 2.5 liters to 2.7 liters, with a rated power output of 163 hp versus 158 hp for the 1988 2.5 liter version. Most 944's were produced with a 5-speed manual transmission, but a small number of 3-speed automatics were made for the base model.