Last year the deVille series was a sedan and a coupe, but this year there was also a touring sedan.
All three had the new 4.9-liter V-8 engine which was linked to the 4T60-E electronically controlled four-speed automatic transmission with overdrive.
An improved version of the Teves anti-lock braking system was also now standard equipment.
Other new standard features of the deVille series included structural enhancements for improved crash-worthiness, 15-inch cast aluminum wheels, and a larger, higher capacity front braking system.
Sedan DeVille 1991
Computer Command Ride was optional and offered three damping modes to enhance ride and handling characteristics.
Formerly optional, but made standard equipment in 1991 were side and decklid accent striping, rear window defogger with heated outside mirrors.
Twilight Sentinel and automatic door locks including a new central door unlocking system.
Appearance-wise, the deVille featured a new power dome hood, wider grille with grid design and integral Cadillac script, revised front bumper guards and rear bumper rub strip, and a 4.9 Port Fuel Injection V8 decklid emblem.
Inside, EZ-Kool solar-control glass for all windows was made standard, Esteem seat cloth replaced the previously used Primavera, and an engine oil life indicator became standard.
A Phaeton roof was optional for the Sedan deVille while both a Cold Weather Package and a Security Package were also new options. The former included a heated windshield system and engine block heater while the latter featured remote keyless entry. illuminated entry and a theft-deterrent system.
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 code was as follows:
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 represented the car line/series, C/D=deVille
Digit six represents the body style: 1=two-door coupe/sedan, 5=four-door sedan
Digit seven identities the restraint code: 1=active (manual) belts, 3=active (manual) belts w/driver’s side airbag, and 4=passive (automatic) belts.
The eighth digit identifies the engine: “B”=L26 4.9L V-8
A check digit follows.
The 10th digit represents the model year, “M” for 1991.
The eleventh digit represents the assembly plant.
The remaining six digits identify the production sequence number.