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1966 Cadillac DeVille Convertible

The DeVille legend continues…


…in the continuing saga of “As the Standard of the World Turns”


America’s favorite luxury car went topless…the result was the drop-dead gorgeous 1966 DeVille convertible. DeVille models offered a rare combination of fine car luxury and elegance with a highly individual flair. The 1966 DeVille convertible’s visual excitement was more than matched by its new performance. The handling ease, was smooth, responsive, quiet…and unsurpassed. The DeVille Series introduced a new dimension in motoring excellence.

The dramatic contemporary luxury was elegantly expressed in the 1966 DeVille convertible. It was the open touring edition of America’s favorite luxury car. And…what could be more charismatic than a RED Cadillac convertible. It so eloquently announced its owner’s arrival. There was no more majestic manner in which to discharge the enigma than this RED DeVille convertible for an encore performance…in the continuing saga of “As the Standard of the World turns.”



New elegance…new excellence…and new excitement were the superlatives of the 1966 Cadillac DeVille convertible ad campaign. Cadillac offered expanded engineering, manufacturing and quality facilities that promised even higher standards of excellence in their restless quest for Cadillac-perfection.

Cadillac was the finest of all luxury automobiles. The 1966 Cadillacs continued the tradition of leadership that created the greatest demand of any luxury motorcar and the highest owner loyalty in the industry. Style code #66-683 68367-F DeVille convertible had a base price of $5,555 and 19,200 were built for the 1966 model year.



The Fleetwood Division of Fisher Body built all Cadillac bodies exclusively to stringent Cadillac quality control standards. The new Cadillac body contributed a greater measure of quietness. With the combination of a low silhouette and low profile tires, the bodysill construction provided a lower step-in height.

The 1966 Cadillacs received the “Cadillac Beauty Treatment.” It was a freshened version of the 1965 bodyshell which had been totally re-worked. New cornering lamps were mounted individually into the fenders separate from the head lamp assemblies. A new Cadillac crest was displayed in a new panel setting.


The new front end design was an all-new ensemble modifying its massive bumper, grille, headlamps, and hood lines to create a distinctive new appearance by fine tuning to a more integrated and unified styling cue. It was understated, yet unmistakably Cadillac. By the mid-1960s Cadillac had tamed its flamboyance into a more refined and unique “poised-dignity.”




The rear end received a new bumper and body-colored valence for a brilliant new appearance. The deck lid was now lower meeting the top of the bumper and rear grille work. Distinctive new rear tail lamps were highlighted by a vertical impact member that not only protected the assembly but also projected light to both sides.



The 1966 Cadillac DeVille convertible had an exclusive sew-style to the interior trim. It used wider and two less pleats than the closed DeVille models. A standard fully leather upholstered interior by Fleetwood augmented its youthful appearance. Front perforated leather bucket seats were optional at extra cost.

These new Strato bucket seats featured slim tapered back rests with optional passenger recliner and head restraints for both front seat passengers. A locking center front console was standard with the Strato bucket seat option. A power fully automatic folding fabric roof was also standard. A stretchable plastic coated fabric convertible boot had a neat tailored look with self-adhesive edging to simplify installation and removal.


Strato bucket seats from the 1966 Eldorado




The 1966 Cadillac DeVille convertible came standard equipped with: power windows, power two-way front seat, front center folding arm rest, electric clock, heater/defroster, cornering lamps, courtesy lighting, power brakes, Variable Ratio Power Steering, Hydra-Matic drive, left-side power outside rear view mirror, seat belts, and windshield wiper/washers.



For the 1966 model year, the Cadillac power train offered refinements which escalated Cadillac’s famed performance to new levels of excellence. The Cadillac V8 engine was designed for maximum efficiency and performance without useless weight or unnecessary bulk. With refinements to engine mounts, and exhaust systems the Cadillac engine delivered its power even more quietly.



Durability was improved even further. New pistons and oil rings were designed for improved oil control and greater durability. The oil pan seals were improved to provide higher compression and more reliable sealing. A new stamped metal water pump impeller with ceramic seal provided extended life. The rear main bearing oil relief groove deflected excess oil into the pan to reduce the load on the rear seal by nearly 90% for improved sealing.


The power was derived from Cadillac’s 7.0 litre 429 CID 16-valve OHV V8 engine. It was equipped with either a Carter AFB 3903S 4-bbl or a Rochester #7026030 4-bbl downdraft Quadrajet with equalized manifold, mechanical fuel pump, dry-type air filter, and automatic choke.

The engine block and cylinder heads were made of cast iron and used five main bearings with hydraulic valve lifters. It produced 340 hp @ 4,600 rpm with 651 Nm of peak torque @ 3,000 rpm. Performance was rated as 0-60 mph in 8.4 seconds, 0-100 mph in 23.7 seconds with a top speed of 127 mph. It could do the ¼ mile @ 88 mph in 16.1 seconds.


Thoughtful amenities for the 1966 model year included a new coaxial resonator the eliminated sound. The coaxial resonator provided certain sound pitches that opposed those from the engine. The result was the most quiet and unobtrusive exhaust systems in the history of the brand. Constant refinement in every area is what kept the brand as the “Standard of the World.”


The engine was mated to GM’s Turbo Hydra-Matic THM-400 3-speed automatic transmission. It was refined to provide noticeably increased smoothness and quiet. The GM Turbo Hydra-Matic offered flexibility meeting varying driving conditions. This flexibility was due in no small part to the use of a variable stator in the torque converter.

With the accelerator pedal depressed halfway, the pitch of the stator vanes permitted maximum torque and acceleration. When less torque was required by less depression to the accelerator pedal, the pitch of the stator vanes reduced.

This aided in precise maneuvering for parking, preventing ‘creeping’ in idle, and acceleration where urgency was not paramount. Improvements for the 1966 model year included substantially increased shift smoothness, quietness, and more reliable stator control.


The GM Turbo Hydra-Matic offered two drive ranges. With the selector in the left “DR” range position assured maximum cruising economy, quietness, and slower engine speeds. With the selector in the right “DR” range this locked out high gear and used the intermediate gear for maximum responsiveness and increased engine braking. This selection was best suited for mountain driving to hold the car on steep downgrades and provide the power and agility to climb the steepest hills.


The 1966 DeVille convertible was built as body on frame construction. It used Cadillac’s fully boxed perimeter frame with hidden bulkheads for additional torsional rigidity. Modifications were made to reduce vibration and road noise. The hidden bulkheads added strength and rigidity. It was made of heavier gauged steel in some frame members.

The Pheasant tail design of the rear engine support cross member permitted engine support without infringing upon front seat interior room. The width of the forward frame allowed the location of front strut rods further outboard for excellent control of fore and aft movement to the front wheels. This design also permitted a lower transmission tunnel height in-car interior.


Two additional frame braces forward added strength, rigidity, and quietness. The frame was cambered to match engine and body loads giving even distribution on all body mounts, and improved alignment of frame to body. New arrangement of body mounts assisted in substantial noise reduction. The 1966 Cadillac DeVille convertible was a very large front engine rear drive vehicle. It rode upon a long 129.5” wheelbase, had the luxury length of 224”, and was 80” wide.


The front suspension used upper and lower control arms. New arrangement of these control arms improved stability and handling. The upper tie-rod pivots and steering arm were raised to improve stability and was made possible through the use of the new Variable Ratio Power Steering.

The front strut rods were mounted to the frame with thick rubber bushings to hold the wheels in firm fore and aft alignment during normal driving yet allow a brief rearward deflection of the wheel when it negotiated uneven pavement or pothole impact.



All other front suspension components were mounted to the frame with rubber bushings to absorb road impact and isolate road noise. Rubber limit bumpers allowed maximum vertical wheel travel to cushion the impact to avoid bottoming out. The front suspension was equipped with spherical joints and independent helical coil springs. The front was also fitted with hydraulic direct-acting shock absorbers with front stabilizer torsion rod.


The rear suspension had modification to the upper control arm to reduce ‘pitching’ for added comfort. The possibility of bottoming out on severe bumps was greatly reduced. The location of the coil springs on the rear axle housing freed the suspension bushings of spring load so they could effectively do their job of isolating road noise.

Wide stance upper control arms resisted sideways motion of the car. Over-size rubber bushings at upper and lower control arm mountings and thick insulation at the top and bottom of springs absorb impact and isolate road noise. It used Cadillac’s four-link drive and hydraulic direct-acting inverted “V” mounted shock absorbers.






Cadillac’s triple braking system was standard for the 1966 model year. A separate fluid reservoir facilitated independent front and rear operation. Master cylinder pistons and hydraulic lines served both front and rear brakes further assisting the power brake’s independence.

The Parking brake was a true auxiliary brake since its vacuum release prevented it from locking when the engine was running and car in gear. The system was fitted with finned duo-servo front and rear drums with self-adjusting feature. The brake cylinder pistons were made of iron alloy and were self-lubricated for long life and resistance to corrosion.


More glamorous than ever, the 1966 Cadillac DeVille convertible was a remarkable example of contemporary styling and design combined with traditional beauty and luxury. It was no doubt a masterpiece from Cadillac. The brand had for many years earned the total respect and admiration of the luxury car world. The 1966 DeVille convertible was an automobile designed for those who required a different way to travel luxuriously in open air touring.

The powerful V8 engine and refined Turbo Hydra-Matic Drive made each journey effortless and enjoyable. In the way it looked and the manner in which it drove, the 1966 Cadillac DeVille convertible introduced a brand new measure of excitement to contemporary luxury motoring…only as the “Standard of the world” could present. This was another brilliant DeVille encore presentation…in the continuing saga of “As the standard of the World Turns.”







The 1966 Eldorado shared the exact same specs as the DeVille



The Eldorado interior featured genuine wood trim











1966 Cadillac DeVille convertible

3 thoughts on “1966 Cadillac DeVille Convertible Leave a comment

  1. Youre so cool! I dont suppose Ive read anything like this before. So good to search out any person with some authentic thoughts on this subject. realy thank you for starting this up. this web site is one thing that’s needed on the internet, someone with a little bit originality. helpful job for bringing something new to the internet!

  2. Your comments on the 1966 Cadillac are spot on.As one who has owned 1937 thru 1975 model Cadillacs,I will put my 1966 Cadillac Fleetwood as the best of any of them.It is even a far better car than what Cadillac has built since then.James McCuskey Jr.

    • Hello JAMES!!!! Yes indeed – we are on the very same page! The LAST REAL Cadillac was built in 1969 & 1970. From 1971, Cadillac was adulterated with so many different parts they became a GM Hodgepodge instead of “The Standard of the World.” The 1966 was among the last of the real cars truly! The way it was made, says it all. I tell folks all the time, GM began cutting their offerings down in size beginning the 1971 model year. They cut everything down on the car, made the ‘greenhouse’ larger – they kept the length, wheelbase, and width – but they were indeed downsized. You can take the 1971-1976 Cadillacs apart with a standard tool kit!

      I tell all who own a classic Cadillac to make sure and keep it operating. They are going to be worth a small fortune one day. Have you seen the way the prices for classic cars have increased in just the last 5-years? Especially Cadillac. The 1960-1970 Cadillac are the all-time favorites for us all!

      Little did we know it, but we were seeing the last of those fabulous motorcars in 1970! As I stated, The 1971-1976 were just GM clones with Cadillac nomenclature! The 1949-1970 Cadillacs are the collector’s dream…the proverbial real-deal! They are truly the last of the breed – the last of the “Standard of the World” – a legend, and an American lifestyle!! Cheers my friend!

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