of '76 In a tie-in with the United States Bicentennial, a Spirit of '76 edition of the Dart Sport featured white paint with prominent red and blue bodyside striping meant to evoke the image of the American flag. Dart Lite In response to increased interest in fuel economy, Dodge offered the Dart Lite fuel economy package which weighed at least less than the ordinary Dart Sport. The 225 slant-six was the only available engine, equipped with an aluminum intake manifold for the first time since 1960 and a specially calibrated carburetor and distributor. Bumper reinforcement brackets were aluminum instead of steel, while the hood and trunk lid bracing and inner panels were also aluminum. The slant-six engine block had already been modified for reduced weight in 1975; in the middle of 1976 production, its crankshaft was changed from forged steel to lighter cast iron. The high-flow exhaust system included a dual-biscuit catalytic converter, a larger 2¼" headpipe, and the muffler used on V8 models. The Dart Lite was equipped with a 2.94:1 rear axle rather than the customary 3.21:1 ratio when the car was ordered with a three- or four-speed manual transmission. The A833OD Overdrive 4-speed manual transmission housing was made of aluminum and had a .73:1 final drive ratio which allowed cruising at highway speeds with minimum engine revolutions. Like all other Darts, the Dart Lites with automatic transmission came with a 2.76:1 rear axle as standard equipment. The Dart Lite with manual transmission was rated by the EPA at 36 mpg (6.5 L/100km) in highway driving. The Plymouth version was the Feather Duster. Taxi Darts were offered to the taxicab industry for their whole production run from 1963 to 1976. While specifications varied by year, interior upgrades generally included heavy-duty front and rear black rubber floor mats, heavy-duty seat cushion springs with full-foam back and air-foam seats, black all-vinyl trim with heavy canvas-backed vinyl seat covers, interior door pull assist straps or handles, and a door-ajar warning light for the driver. Mechanically, Dart taxicabs were generally equipped with heavy-duty brakes, tires, shock absorbers, front torsion bars and rear leaf springs, a high-output alternator, an increased-capacity cooling system, and extra-lean carburetor calibration for greater economy. In 1976, the Chrome Yellow taxi package was available only with a 225 slant-six engine producing and ; transmission was the (rare) A-727-RG (raised-deck motor, which was the slant-six series) with California emissions, and