Home Travel Stories Gas Logs 1972 DODGE Demon 225-1 bbl MPG= 18.4 City
1972 DODGE Demon 225-1 bbl MPG= 18.4 City PDF Print E-mail
Written by Double Dragon
Monday, 04 August 2014 21:37

1972 DODGE Demon 225-1 bbl MPG= 18.4 City


Writing and photography copyright D. S. Brown

Metric=  3.7 L engine -18 L/100 km


1972 Dodge Dart Demon 225 1 barrel when new MPG= 16.4 overall.

The Dodge Dart Demon was an economy car in price and size but not looks. By today's standards it's a medium sized car roughly equal to today's ponycars which are now frankly quite large. The two door Dart Demon 108 inch wheelbase matches the wheel base of ponycars of the 1960s era but adds a usable sized rear trunk which packs on extra length.

Parking the 1972 Demon beside a 2013 Mustang it's evident that they are within inches of each other in length. The more rounded roof of the Mustang is slightly taller at its peak dimension and of course the 19 inch wheels with matched rotors look positively huge beside the Demon's 14 inch steelies. The Demon's 108 inch wheelbase traces back to the Duster from which most of the 'racy' sheetmetal was sourced.

The standard Demon engine is a 100 HP slant six 198 cubic inch engine with a single barrel carburetor. WORLD CARS 1972 estimated 17.2 MPG for this car. Many buyers moved up to the 225 cubic inch one barrel slant six which produces 110 HP and 16.4 MPG according to WC. The Dodge Dart used to calculate these results had the 3 speed manual shifter coupled to 3.23 axle ratio and 6.95x 14 inch tires. Upgrading from a 198 to a 225 raised top speed from 92 to 98 MPH according to WC's calculations. The optional engine adds 11 pounds to the 2,940 pound car. It is likely the Demon may add slightly more MPG and extra speed to the Dart figures due to its fastback design. Weight is also quoted as 2,888 pounds for the 6 cylinder Demons regardless of 198 or optional 225. Putting the Torqueflite auto transmission in this car lowers rear axle to 2.76:1.

LEMON AID 1981 EDITION says a 4 door Dart with 6 cylinder engine, automatic transmission and radio weighs around 2,900 pounds. LA estimated MPG to be 20 MPG using regular fuel. LA doesn't specify if the MPG is overall average but does say that the MPG quoted is what the car is optimally capable of under ideal conditions.

WC estimated 318 2 barrel MPG to be 13.9 and top speed at 104 MPH. Weight balloons to 3,015 pounds when the V8 is dropped into the car. In the Dec, 1972 issue of MECHANIX ILLUSTRATED Uncle Tom McCahill tested a 1973 Dart Sport 340 which suffers from extra weight (5 MPH bumpers), less compression and more smog equipment and it still managed an impressive 115 MPH top speed through a 3.23 rear axle and running Goodyear E70x14s.


OOCC 1972 Dodge Dart Demon City MPG

The OOCC Dart Demon was purchased Nov 16, 1971 by Josephine from Tom Matson's Valley Motors in Auburn, Washington. To read a story about Tom Matson Dodge see the WASHINGTON/ Seattle Area stories filed in the DEALERSHIPS section of this website. See the story of Josehine and her Demon filed in this website in the ONE OWNER section of the CAR STORIES.

Josephine bought her Demon off the lot equipped with optional larger 225 slant six, power steering, automatic transmission, manual drum brakes, and tinted windshield. Her Demon lacked power brakes, rear defroster, or even a radio. The car came with the radio delete block off plate covering the dashboard radio location.

The VIN decodes as follows:

L= Dart or Demon

L= Low Price Class

29= Two Door Sports Hardtop

C= 225- 1 barrel six cylinder engine (145 HP gross/ 110 HP net)

2= 1972 Model year

B= Hamtramck, Michigan final assembly plant.

The final digit sequence is not shown here to protect owner privacy. The fender tag tells us that the car had a scheduled build date of August 24, 1971. The Demon is equipped with the D34 Light duty automatic transmission. The car is painted Powder Blue exterior paint with Bright Blue Poly interior door frame tops. The interior Trim level is 'Luxury' with Blue vinyl bench seat. The Demon has G15 Tinted windshield, J25 3 Speed wipers, and M31 Belt moldings.

The only driving accident suffered came early in the life of the car. Another driver hit the driver's door which had to be removed for repair and repaint. The frame is still straight and true which lets the car roll easily and helps the car reach optimal MPG.

In the 1970s the radio delete block off plate was removed and an aftermarket stereo installed. Two speakers were installed in the rear package tray. Otherwise no modifications were ever made to the Demon. The radio and speakers add about 15 pounds to the car.

The brake master cylinder has been replaced twice and a remanufactured carburetor was installed. The original exhaust tail pipe hangers were re-used on a new exhaust system. Otherwise everything is original and retains factory stock settings. The only deviation from stock equipment is a switch to radial tires which create less rolling resistance and improve MPG. The Goodyear radials are set to 30 PSI front and 32 PSI rear. The Demon has 4 wheel drum brakes which produce less rolling resistance than disc brakes.

The Demon was driven sparingly for 70,000 miles until sold April, 2013. The logs below document driving with new P185/ 75R14 Goodyear Regatta 2 radial M + S tires set at 30 to 32 PSI. 10W30 engine oil was used. The gas fills vary between 91 to 94 octane Chevron brand with Sta-bil added at most fills. The Demon was driven on sunny 80 degree F days in slow careful city driving.

Average speeds were about 35 MPH carrying approximately 700 pounds with all windows rolled down. Open windows create a parachute effect as the engine strains to pull against the resistance of the rear window. The rear pop out windows were always fully open which is only about one inch but this obstruction into the airflow lowers the co efficient of drag a touch. The radio was off saving some extra engine energy, but the antenna was fully extended which might add a smidgen of drag. Lights were off so the engine didn't have any additional drain to overcome through the alternator. The lower roofline and narrower top to the roof of the fastback Demon body is quieter than a 1972 Dodge Dart Swinger which implies that the wind resistance is lower which aids MPG. The 'stripped' condition of the Demon means that the base car weighs under 3,000 pounds somewhere around 2,888 pounds curb.

Odometer  Gallons   Octane  Full Tank?   MPG (uncorrected)

70,695.2       10.3      94      3/4 full        n.a. MPG

70.000.0        2.8      89      Full Tank      n.a. MPG

70,000.0        3.5      89      ?                 n.a. MPG

70,795.3        2.6       94      Full Tank      n.a. MPG

70,836.7        2.9      89       3/4 full        n.a. MPG

70,000.0        2.9      89       ?                 n.a. MPG

70,870.7        4.1      91       Full Tank     18.4 MPG

Last Updated ( Saturday, 20 March 2021 08:50 )