Cadillac Allante History 1991

Cadillac Allante Models & History 1991

The Allante was once again available as a convertible or as a convertible hardtop that included both a convertible top and a removable all-aluminum hardtop.

The engine (cast iron cylinders in aluminum) was the same 4.5 liter V8 and F-7 four-speed automatic transaxle that was used in 1990. However, the engine had a new air intake resonator for quieter performance. The resonator remove a little bit of the roar when driving up a hill, but the exhaust note was the same as in 1990. Engine power was improved through the use of straighter intake ports and larger valves (45mm intake and 38mm exhaust). The exhaust was evacuataed through thin-wall, cast iron manifolds that were shaped for minimum flow resistance. Also, to help reeduce oil aeration, a new gearotor-type oil pump was added to the engine.

The convertible featured an improved, Phase II ergonomically-designed, power-fastening, folding soft top.

Inside, the Allante’s previous light charcoal interior carpeting and floor mats were replaced with dark charcoal counterparts.



  • 90-degree, overhead valve, V-8, aluminum block and cast iron cylinder liners, cast iron cylinder heads
  • Displacement: 273 cu. in. (4.5 liters)
  • Bore & Stroke: 3.62 in. x 3.31 in.
  • Compression ratio: 9.0:1
  • Brake horsepower: 200 @ 4400 rpm
  • Torque: 270 lb.-ft. @ 3200 rpm
  • Five main bearings
  • Roller hydrauic valve lifters
  • Tuned port fuel injection


Wheelbase 99.4 in 2.525 m
Overall length 178.7 in 4.539m
Height 51.2 in 1.3m
Width 73.5 in 1.867m
Front tread 60.3 in 1.532m
Rear tread 60.4 in 1.534m
Standard tire Goodyear Eagle VL P225/55VR16




  • Transmission: THM-F7 automatic four-speed transaxle (includes viscous converter clutch)
  • Steering: Power-assisted rack and pinion
  • Steering Ratio: 15.6:1
  • Front suspension: Independent MacPherson strut with coil springs, strut-type shock absorbers, integral-in strut and electronic variable, and stabilizer bar
  • Rear suspension: Fully independent transverse monoleaf with integral-instrut electronic variable shock absorbers, no rear stabilizer
  • Brakes: Power assisted front disc and rear disc with Bosch II ABS
  • Body construction: integral body-frame
  • Fuel tank: 22 gal.
  • Curb Weight: 3537 lb


  • Standard Seating: 2
  • Headroom – front (in.): 37.2
  • Legroom – front (in.): 43.2
  • Hip Room – front (in.): 54.4
  • Shoulder Room – front: 57.7 in.
  • Turning Diameter (left): 40
  • Turning Diameter (right): 40
  • Fuel Economy (city / hwy): 15 / 22 mpg (US)


  • digital instrument cluster (convertible only) $495
  • pearl white paint (convertible only) $700