The 1989–1990 Ultradrive equipped models came with a 2.36:1 axle ratio, which was revised to 2.52:1 for 1991–1993. EPA mileage ratings were 21 city/25 highway MPG with the 4-cylinder and 3-speed TorqueFlite transmission. The 1988 3.0 L V6 models with TorqueFlight transmission were rated at 18 city / 24 highway MPG. In 1989 the EPA rating for the 3.0/Ultradrive power-train changed to 18 city / 26 highway MPG. The new 3.3 L V6 engine for 1990, with Ultradrive transmission, was rated at 19 city/ 26 highway MPG. A 2.5-litre inline-4 Chrysler engine (base model only), a Mitsubishi-sourced 3.0 L V6, the 6G72 engine, and a Chrysler-built 3.3 L V6 were available, although the 3.3 L V6 was not available until 1990. The four-cylinder came equipped with a TorqueFlite three-speed automatic transmission (the A413), as did the 3.0 L in 1988. The new electronically controlled four-speed automatic transmission, known as the Ultradrive or A604 (List of Chrysler transmissions), debuted in 1989, and became the sole transmission for V6 models through the 1993 final production year of the Dynasty. The vast majority of Dynastys sold to private customers had V6 engines; four-cylinder models mostly went to the fleet market.