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.
I. D. NUMBERS
The 1991 Cadillac had a 17-symbol vehicle identification number (VIN) stamped on a metal tag attached to the upper left surface of the cowl visible through the windshield.
The first digit “1” represented the manufacturing country (United States)
The second “G” represented General Motors
The third “6” represented Cadillac
The fourth and fifth “VR” represented Allante convertible hardtop
The fourth and fifth “VS” represented Allante convertible
The sixth “3” represented the body style: convertible
The seventh “1” represented active (manual) belts
The seventh “3” represented active (manual) belts with driver’s side airbag
The seventh “4” represented passive (automatic) belts
The eighth “8” represented the LQ6 4.5L V-8
The ninth is a check digit
The tenth “M” is the model year for 1991
The eleventh is the assembly plant
The remaining six digits identify the production sequence number