[aerohead]

Slow, I located some original road test data for the 1981 year model of your car, from Popular Science, and Road & Track:
* Cd 0.48
* Af approx. 24.3379-square-feet ( 2.26106 meters-sq .)
* CdA approx. 11.6822- sq-ft ( 1.08531 meters-sq. )
* Curb weight 4,052-lb ( 1,833.48-kg )
* 302 CID V8, with throttle body fuel injection
* 4-spd automatic transmission, with lockup torque converter
* 3.08:1 rear axle ratio
* Fineness ratio- 3.648639
* Tires- P205/75R15 Uniroyal Royal Seal steel-belted radials
* Length- 216-inches ( 5486.4mm )
* Width- 78.1-inches ( 1,983.74mm )
* Height- 55.4-inches ( 1,407mm )
* Ground clearance- 6.5-inches ( 165.1mm )
* 18-gallons
* 23.5-mpg @ 35-mph ( 56.3 km/h ) observed
* 17.8-mpg @ 55-mph ( 88.56 km/h )
* This 1981 model is physically identical to the 1976 year model and remained unchanged until 1984.
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The 1984 Mark VII was shorter, narrower, lighter, and lower drag:
* Cd 0.38
* Af approx. 21.894-sq-ft ( 2.03409 m-sq )
* CdA approx. 8.32-sq-ft ( 0.7729 m-sq )
* EBLA = 15.5-degrees
* Tires- Goodyear Eagle GT P215 / 65R-15
* Fineness ratio approx. 3.84682
* 60-degree windshield
* 63-degree backlight
* Curb Weight 3,735-lb ( 1,690.04 kg )
* 302 CID V8 w/ TBI, and 3-way catalyst
* BMW 6-cyl diesel
* 4-speed automatic with lockup torque converter
* 34.0-mph/ 1,000 rpm gearing
* piston speed = 885- surface feet/minute
* 1,765-rpm @ 60-mph ( 96.6 km/h )
* 22.1-gallons tank
* 16-mpg 'normal' driving ( I have no idea what they mean ! )[ Road & Track ]
* 340-miles range, with 1-gallon reserve
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1993 Lincoln Mark VIII
* 17.0-mpg ave. ( Motor Trend )
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1998 Lincoln Town Car: ( from Popular Science )
* 23.5-mpg 'best'
* 17.3-mpg 'worst'
* 21.1-mpg 'average'