Though sharing a common chassis architecture, the Cougar was visibly distinguished, ranging in degree from distinct grilles, badging, and lighting components to nearly every body panel specific to the model line.

The rear fascia was styled similarly, concealing dark-lens taillamps behind vertically-slatted trim; sequential turn signals were standard (adopting the mechanism from the Thunderbird).

[17] For 1970, the Cougar underwent an additional revision to the front fascia; the split "electric shaver" grille with vertically slatted trim made its return, with a new hood adopting a pronounced body-color center section.

Standard was the a 390 cubic-inch "Marauder GT" V8 (320 hp) as well as upgraded suspension, larger brakes, wheels, and tires, and a low-restriction exhaust system.

[22] Offering a racing-derived 390 hp 427 V8 (paired solely with a 3-speed automatic[9]), the GT-E included special badging, quad exhaust, argent lower body paint delineated by chrome trim, and a redesigned grille; power front disc brakes were standard.

These included the 351W-4V engine, a front air dam and body-colored rear spoiler, styled steel wheels (similar to the 1969 Mach 1 wheels), a black-out front grille, body-colored hood scoop (only functional with ram-air 428CJ engine), Eliminator-specific body side stripes in white or black (keyed to paint and trim color), left-hand remote-control racing-style side mirror, heavy-duty suspension, and a performance axle.

The Special Paint Order option was also available for Eliminators in 1970, producing single-digit examples in colors such as Black, Light Gray Metallic, White, and Red.

Slightly smaller than the 1965 Mustang, the imported Capri (not officially badged as a Mercury) began to succeed the Cougar within Lincoln-Mercury as a compact sporty car.

One of the few American model lines that would eschew downsizing during the mid-1970s, the Cougar grew in size, sharing its body with the Mercury Montego and the later introduced Ford (Gran Torino) Elite.

Initially, at risk for cancellation (following declining sales of the second generation compared to its competitors), Lincoln-Mercury instead repackaged the Cougar as a halo car for the Mercury brand.

Now serving as the flagship model of the Cougar line, the XR-7 was now the direct Mercury equivalent of the Ford Thunderbird; for 1977, the latter had shifted from the Mark IV to the Torino chassis (replacing the Elite).

The XR-7 included power disc brakes and steering, 15-inch wheels, a rear stabilizer bar, walnut wood-tone instrument panel, a Flight Bench seat, "XR-7" trunk key-hole door, "COUGAR" decklid script, large hood ornament (with cat emblem), and sport-styled roofline with back-half vinyl and rear opera side windows and louvers.

For 1981, Mercury added a standard-trim Cougar, replacing the Monarch as its mid-size offering; the line shared its two-door and four-door sedan body with the second-generation Ford Granada.

In its development, many design elements of the 1977–1979 Cougar XR-7 were carried forward in the fifth-generation redesign, including its Continental-style trunk lid, louvered opera windows, and sharp-edged fender lines.

While the fourth-generation Cougar XR-7 had proven successful in the marketplace, the design elements fell out of proportion on a radically smaller car, leading to negative reception.

In what would prove disastrous, the Cougar saw little to no differentiation from its Ford counterparts, with the XR-7 externally distinguished from the Thunderbird only by its grille, taillamps, trunklid, and usage of exposed headlamps.

[58] 1986 saw few changes, highlighted by the addition center rear brake light (CHMSL) and a power-operated moonroof;[59] for the last time, the Cougar was available with vent windows.

[57] To further distinguish the model line from the Thunderbird, the 1987 Cougar received its own grille (with a large "cat" emblem), front bumper cover, and aerodynamic composite headlamps.

[65] The 20th Anniversary Cougar included the 4.9 L (302 cu in) V8, sport-handling suspension with quad rear shocks (derived from the XR7), and 15-inch alloy wheels (from the Mustang GT, painted gold).

[66] Developed from the second quarter of 1984, as a counterpart of the tenth-generation Ford Thunderbird, the $2 billion redesign of the two vehicles was intended to create handling benchmarked against far more expensive coupes (BMW 6-Series, Mercedes-Benz 560SEC, Jaguar XJS) while remaining in the same price segment.

As market demand shifted away from large two-door coupes, the Mercury Cougar and Ford Thunderbird were discontinued after the 1997 model year, with the final example produced on 4 September 1997.

For 1991, a 200 hp (149 kW) version of the 4.9 L (302 cu in) Windsor 5.0 was introduced featuring a redesigned intake manifold to allow sufficient underhood clearance for the engine to be installed.

[66] Originally slated to be launched with dual airbags, cost overruns and market demand necessitated the use of automatic seatbelts to meet passive-restraint requirements.

In addition to the 210 hp (157 kW; 213 PS) supercharged V6 (replaced by a 5.0 L V8 in 1991), the XR7 featured four-wheel antilock disc brakes, electronically adjustable handling suspension, 16-inch alloy wheels, and a 5-speed manual transmission.

[72][73] For 1993, Mercury revised the Cougar model line, with the XR7 becoming the sole trim level, dropping the LS and the monochromatic sport-oriented XR7 (eliminating some overlap with the Ford Thunderbird).

"Sport Package" models of the V6 featured four-wheel vented disc brakes (from the Contour SVT), 16-inch alloy wheels, fog lights, and the speed governor raised, not removed; contrary to popular belief.

This generation of Cougar had a far more contemporary package, with modern DOHC 24-valve six-cylinder Duratec engines, a fully independent multilink suspension, and front-wheel drive.

The Cougar's body, and the New Edge idea in general, was introduced as a concept called the Mercury MC2 in 1997 and was considered a bigger version of the European Ford Puma.

In 1967, NASCAR race car builder, Bud Moore, campaigned Mercury Cougars in the Trans-Am Series with Ford Motor Company factory support.

The Wood Brothers Racing team with David Pearson and later Neil Bonnett was successful with the car and scored several victories until the body style became ineligible following the 1980 season.