Anti-lock brakes became standard equipment in all Cadillacs in 1991.

• The 4.5-liter V-8 formerly used to power most Cadillacs was replaced by a more powerful 4.9-liter V-8 with port fuel injection. This new engine saw service in DeVille/Fleetwood, Eldorado, and Seville models.
• Also new, and coupled to the 4.9-liter V-8, was the 4T60-E electronically controlled four-speed automatic transmission with overdrive.
• The rear-wheel drive Brougham sedan's standard 5.0-liter V-8 received fuel injection and delivered 21 percent more horsepower (up to 170) over the previous year's carbureted unit.
• Computer Command Ride was new to Fleetwood, Seville, and Eldorado. It had automatically adjusted struts to provide increased damping and road control as those vehicles' speed increased.