In the interest of fuel economy, the 1977 Continental Mark V was equipped with the smallest-displacement engine fitted in a Lincoln or Continental since 1957. Shared with the Ford Thunderbird/Mercury Cougar and Ford LTD/Mercury Marquis, the standard engine for the Mark V was a 400 cubic-inch V8. Outside of California, the 460 V8 remained available as an option. In 1979, the dual-exhaust version of the 400 was discontinued; the 460 was discontinued in the Mark V (and in all Lincolns by 1980). Paired with both engines, the Ford C6 three-speed automatic was the sole transmission offering. Marketed as the flagship vehicle of the Lincoln-Mercury Division, the Continental Mark V showcased a new design theme for the Lincoln brand, with styling features from the Mark V appearing on various Lincoln vehicles throughout the 1980s. The exterior design of the Mark V began life in the late 1960s, as an alternative design proposal for what would become the Continental Mark IV. During the development of the Mark V, chassis designers intended for the vehicle to use specially-designed (wider) Michelin tires, leading to widely flared wheel openings in the design. Alongside the Lincoln Continental, the Mark V was styled with sharp-edged fender lines. In contrast to Lincoln design precedents, the Mark V shifted towards horizontal edges, with a nearly flat roofline. To increase visibility, the rear window and quarter windows were enlarged. In Mark-series tradition, the Mark V retained the Continental "spare tire" decklid, oval opera windows, hidden headlights, and a radiator-style grille; the front fenders were given functional louvers behind the front wheels as standard equipment. In a style similar to the Mark III, the Mark V was designed with vertical dual taillamps. During its development, stylists initially designed taillamps that curved into top of the rear fender blades; the design was modified after controversial reviews from focus groups. While technically considered a $187 option, all Mark Vs were fitted with a vinyl roof unless specifically ordered without one. For 1979, the vinyl roof could no longer be deleted. Previously standard issue on Marks III and IV, Ford's 7.5-liter (460 cid) V8 (now the industry's largest remaining) was optional for 1977, as a smaller 6.6 L (400 cid) V8 became standard. The 7.5 L V8 was not available at all on Mark V in the state of California, as the powerplant was unable to meet that state's tougher EPA certification standards.