1966 Mercury Cyclone GT

1966 Mercury Cyclone GT

Ford’s Mercury division has been synonymous with mid-price luxury transportation. But few know that the division that gave us the “Breezeway” retracting rear window also built one of America’s first factory muscle cars. In 1958, Mercury released a dealer-installed Super Marauder tri-power option for its 430 cubic-inch big-block engine. Adding tri-power bumped up advertised horsepower to an incredible 400, and helped

contribute to making Mercury a performance powerhouse. The option was short lived and by the early-1960s Mercury took a back seat to Ford, their lower priced cousin, in the manufacturing of tire-melting performance cars.

By 1966, Mercury was once again anxious to get back into the muscle car arena. Using the midsize Comet platform, engineers put their collective heads together to develop

A Powerful & Rare Mercury For Under $10k (cont)

the Comet Cyclone and Cyclone GT. The standard Cyclone included all the visuals necessary to identify it as a muscle car, but powertrains were limited to a 289 cubic-inch small-block and a 265 or 275-horsepower, 390 cubic-inch engine, depending on the transmission ordered. A two-barrel carburetor topped the base Cyclone 390. While providing adequate performance, it simply wasn’t enough to keep up with other factory muscle cars of the time. For enthusiasts who wanted neck-snapping performance, ordering a Cyclone GT was a necessity. Under the Cyclone GT’s hood rested Ford’s 335-horsepower, 390 FE engine. This powerhouse included a Holley four-barrel carburetor mounted on a cast iron intake manifold. Its 10.5:1 compression ratio required premium fuel, and dual exhausts were standard equipment. An engine dress-up kit finished off the underhood niceties. All GTs were equipped with a 3.25:1 axle unless otherwise specified.

To improve ride quality and interior space for 1966, the wheelbase was increased two inches, to 116. Overall vehicle length was stretched to 203 inches, adding seven inches to the 1965 specifications. Body width was also increased to add additional shoulder room. Doors had curved glass and for the first time, air conditioning was a factory-installed option. A padded dash and seatbelts

were standard. New options for 1966 were power windows and a two-way power seat. An improved heater and sound-deadening package provided additional comfort to passengers

Mercury Cyclone

Outside, the Cyclone GT was nearly a mirror image of Ford’s Fairlane with a slab-sided body, a front end with dual stacked headlamps, and a wide grille split horizontally by a body colored division bar. All GTs included a standard fiberglass hood with dual non-functional scoops. While it didn’t add any horsepower, the hood certainly added to the visual effect of the GT being a performance vehicle. From the side, a special identification stripe ran across the lower body section. Simple horizontal taillamps rested in the rear tail panel.

All GT models included bucket seats, heavy-duty suspension, body striping, special wheels, and dual exhausts. Transmission availability was limited to a floor mounted standard three-speed manual,

A Powerful & Rare Mercury For Under $10k (cont)

four-speed manual, or three-speed automatic. The Comet Cyclone GT wasn’t the hit the Mercury division had hoped for, selling only 15,970 during the model year. Perhaps it was the additional cost of buying a Mercury, or perhaps the stigma of believing a Mercury wasn’t a real performance car.

However, time has validated the Cyclone GT as a true performance car, and today it is a highly sought after muscle car for Ford and Mercury enthusiasts.

Special thanks to Melvin Benzaquen at Classic Restorations and car owner Geoff Malloy for allowing us to shoot this Cyclone GT.

Mercury Cyclone

Fuel For Thought
Mercury’s premium midsize muscle car

Convertibles are rare with only 2,158 produced

390’s oil capacity reduced by one quart, to four

All GT models included engine dress-up kit

Available with optional nine-inch television

A Powerful & Rare Mercury For Under $10k (cont)


  • Number built – 15,970
  • Construction – Unibody
  • Engine – 390 cubic-inch V-8
  • Power/Torque – 390 cubic-inch V-8, 335 horsepower, 427 lb-ft torque
  • Transmissions – Three-speed manual, four-speed manual, three-speed automatic
  • Suspension front – Single lower control arm, A-type upper control arm, independent coil springs
  • Suspension rear – Semi-elliptical leaf springs with four leafs
  • Steering – Re-circulating ball and nut
  • Brakes – Front disc, rear drum
  • Length/width/height – 203/73.8/54.3 inches
  • Wheelbase – 116 inches
  • Weight – 3,374 lbs.
  • 0-60mph/quarter-mile – 6.6 seconds, 15.2 seconds at 90 mph (Car Life, April 1966)
  • Top speed – 120 mph (Car Life, April 1966)
  • MPG – 10.1 mpg (Car Life road test)
  • Price – MSRP – $3,152; Today – $5,625 – $17,100

Engine – Ford’s FE block was reliable and dependable, but didn’t perform on par with GM’s and Chrysler’s big-blocks. The FE later grew into the renowned 428 Cobra Jet.

Handling – Typical of most intermediates of the time, the Comet was best suited for straight-line acceleration. Cornering was improved over the 1965 model, with longer rear leaf springs and a stiffer front suspension. Those cars equipped with 390s had the curse of a heavy front end, causing excessive leaning in corners.

Mercury Interior

Strong Points
Excellent performance
Low production numbers
Room for five

A Powerful & Rare Mercury For Under $10k (cont)

Weak Points
It’s a Mercury
Un-restored vehicles can have rust issues
NOS and aftermarket parts somewhat difficult to find
Performance not on par with other factory muscle cars

Vehicle Category
Many Cyclones are used on a semi-regular basis. They go to weekly cruise nights and are also shown at local shows. Few are trailered to events. While not as big as other groups, the Comet Cyclone GT enthusiasts are just as enthusiastic.


Mercury Comet & Cyclone Limited Edition Extra 1960-1975 by R. M. Clarke
Standard Catalog of American Muscle Cars 1960-1972 by John Gunnell
Mercury Muscle Cars (Musclecar Color History) by David Newhardt
1966 Comet, Falcon, Fairlane and Mustang Shop Manual by Ford Motor Company
Muscle Cars Field Guide: American Supercars 1960-2000 by John Gunnell

The Cyclone GT was Mercury’s version of a factory hot rod. It established Ford’s premium division as a contributor to the glory days of performance cars.

1966 Mercury Cyclone Gallery