Rewind Review: 1959 Cadillac Cyclone XP-74 Concept Is What Dreams Are Made Of

Motor Trend

06-05-2025

This article first appeared in the Summer 2011 issue of MotorTrend Classic.
He's encrusted in the hub of the steering wheel, St. Christopher. He's the patron saint of travelers, embossed in the medal typically found on the dashboards of faithful Roman Catholics worldwide. 'St. Christopher, protect us,' it reads.
Indeed. Ed Welburn doesn't want me to drive the car. MotorTrend Classic always drives the subject, even priceless Motorama dream cars that can't, or shouldn't, be driven more than a quarter mile at 30 mph tops. Slow, careful drives say something about acceleration, braking, handling, ride, and what kind of vibe a car exudes.
Welburn was about 9 years old when he saw the Cadillac Cyclone at an auto show in his native Philadelphia, probably in early 1960.
'I just remember it was white, with big fins, in a bed of angel hair.'
Welburn's father had taught Ed how to draw at age 3. When he saw the XP-74 Cadillac Cyclone six years later, the younger Welburn decided, right then and there, what he wanted to be.
'At age 11, I wrote GM and told them I wanted to be a car designer when I grew up. I asked for information, schools, training. They sent good information,' Welburn said in a 2008 Motor Trend interview.
GM hired Welburn, its first African-American designer, in 1972.
The XP-74 was Harley Earl's last gasp, his final 'dream car' before retiring and turning the candy-store keys over to Bill Mitchell. Alfred P. Sloan hired Earl, GM's first design chief, in 1927. Earl hired Mitchell in December 1935, and after serving in the Navy during World War II followed by a stint at Earl's private company, Mitchell returned to GM. He finally replaced his mentor on December 1, 1958, just as the automaker's 1959s were catching up with Chrysler's longer, lower, wider 1957 models.
Though Earl was 65, timing was key. Earl's aesthetic was slipping as he added more chrome and gingerbread to cars like the 1958 Oldsmobiles, Buicks, and Cadillacs. His proposals for the '59 models would have carried over '58 bodies. A year before Earl's retirement, he was 'assigned' overseas while Mitchell took over '59 styling, resulting in new bodies from the 'batwing' Chevrolet Impala to the outrageously finned Cadillacs.
Earl returned to Detroit in time to foster XP-74 in spring 1958. Called a running show car in memos preserved at the GM Heritage Center, it's rendered in steel, not fiberglass. Cadillac unveiled the Cyclone on February 21, 1959, part of the week-long grand opening of the Daytona International Speedway in Florida. Though Earl had already retired, he appeared as a 'consultant' to introduce the Cyclone, which by now belonged to Mitchell.
Veteran GM designer Carl Renner is credited with drawing the '59 Cyclone, which predicts the '61 Cadillac profile. Single large, round, afterburner taillamps hint at the '61's dual round lamps housed in chrome nacelles. Though jet aircraft-inspired, the nose cones bookending the grille are as much Jayne Mansfield as McDonnell F3H Demon. Quad headlamps flip up from the grille. Built as a unibody, the Cyclone is 196.9 inches long on a 104-inch wheelbase, and is 44 inches tall. All 1959 Cadillacs, except for Series 75, were 225 inches long on a 130-inch wheelbase.
'It was Mitchell's first opportunity to impact Cadillac,' Welburn says. 'It's lean, more sheer, a smaller Cadillac.
This is the bridge car. It's more Harley Earl than Bill Mitchell, but it has Bill Mitchell's influence.'
The 390-cubic-inch V-8 is out of the '59 Cadillac catalog. Early memos indicate Cadillac was supposed to supply a fuel-injection system, though it has a low-profile four-barrel Carter carburetor to clear the low hood. It's listed at 325 horsepower, 20 ponies short of the production Cadillacs. There are no specs for maximum rpm or torque. Other modifications include a crossflow aluminum radiator and two fans. A two-speed rear axle doubles the Hydramatic transmission's gear ratios. The floor-mounted gearshift offers, from top to bottom, right and left, P, N, 6, 5, 4, 3, 2, 1 and R, with a red lever to switch from the odd-numbered forward gears on the left to the even-numbered forward gears on the right.
The car has proximity sensors in the nose cones, designed to follow sensors imbedded in a road, preventing crashes and allowing hands-free driving. The jet-fighter bubble top was designed to rise automatically when sensors detected rain. The two doors slide back minivan-style and the one-piece rear clip stows the bubble-top, clamshell-style.
GM rushed its Phase I build up one month to December 1958, and unveiled the Cyclone without such items as the proximity sensors or a properly working transmission, in order to get it to Daytona by February. Mitchell scheduled Phase II and Phase III after Daytona. Phase II returned XP-74 'to Styling for modifications, repairs and completion, and installation of originally planned equipment,' so the Cyclone would be ready for 'various displays around the country,' or car shows, according to a March 4, 1959, memo from GM program planner R.L. Dressel. Phase III would prepare XP-74 for road use.
Earl's XP-74 was painted white, with GM Air Transport logos on the outer faces of the tailfins. Mitchell wanted to quickly replace the '59-high tailfins with the ones you see now and to respray the car Silver Pearlescent Lucite. His new fins would have hinted at the '61 Cadillacs' upper fins. The fins on the lower-rear fuselage of both versions already predicted the '61 models' styling.
Redoing an existing Motorama, dream, or concept car was Mitchell's style more than Earl's. Under Earl, Motoramas seemed to have at least one new concept per division virtually every year beginning in 1949. With Motoramas winding down, Mitchell regularly updated and upgraded certain concepts without building an all-new 'property,' as they're known. Consider the way he regularly updated running Corvette concepts.
Mitchell first hoped to redo the paint and tailfins immediately after Daytona, for the 1959 auto show circuit. A memo dated April 2, 1959, reversed this. 'According to Mr. W.L. Mitchell's verbal instructions, the existing tailfins on the rear deck panel of the subject automobile will remain intact for Phase II. The fabrication of the new-design tailfins will continue, and the finished parts will be installed for Phase III,' reads the memo, signed by one W.C. Skelly.
Phase II installed a locking mechanism to hold the canopy onto the body rather than the windshield header, while Delco installed the radar components in the nose cones. A luggage rack planned since Phase I apparently never happened. One memo suggested St. Christopher would be replaced with a speed sentinel in the steering-wheel hub, but that change was scrubbed as well.
The Cyclone made the rounds of the auto-show circuit with its '59-style fins through early 1964, according to the memos. It appears Mitchell lost interest in updating Earl's car after Phase II. With the Motoramas ending after 1961, Mitchell was incredibly prolific during these years, in charge of designs of numerous Corvette concepts, the C2 and C3 Stingrays, the Buick Riviera, the '64 A-bodies (Chevelle et al) and the '65 B- and C-bodies, to name a few.
The fins finally came down about April 1964. GM planned to present the revised XP-74 at the New York International Auto Show that month, then delayed its reintroduction for the New York World's Fair, where it replaced the XP-777 Monza GT Coupe on the United Delco display. Mitchell's new fins came with a paint job, a new eggcrate radiator grille, redesigned center knockoff hubs for the wheel covers, and revised backup and brake lamps. The Cyclone was scheduled to be on display at the World's Fair through November 1964. By that time, Cadillac would have introduced all-new 1965 models, which replaced the '64 fin design that more closely resembled the Cyclone's. The XP-74 went on to appear in a few Canadian shows in 1966 and '67.
Welburn became GM's design vice president in 2003. In the last eight years, he's revitalized the department, reviving Studio X, the super-secret design chamber few top executives could find on their own. On the side, he's brought out such gems as the Cadillac Cyclone for inspiration. He's no more interested in 'retro' styling than peers at competing companies. The Earl and Mitchell era define each GM brand's DNA. The Cyclone represents the epoch of the aerospace influence, which Earl launched with soft, subtle fins on the 1948 Cadillac, 'to the point that the whole body was a fuselage,' like the 1959-60 Cyclone.
Designers often sketched a proposal with the car parked next to a jet aircraft. 'Car design got really inspired from that,' he says. The XP-74 is part of the very fabric of GM, and especially Cadillac, design.
I must drive the XP-74, even if Welburn would rather talk about it and have it photographed. The design chief finally gives in with these chilling words: 'Just keep in the back of your mind that you're driving my childhood dream.'
The limited speeds allowed on GM's Warren, Michigan, campus won't be a concern, though employees in Chevy Volts, GMC Terrains, and Buick LaCrosses zip around without concern for a 52-year-old heirloom lumbering about. The Cyclone is a real car and can be driven like any Eisenhower/JFK-era Caddy. Like all those surviving '57-60 Pinin Farina Eldorado Broughams, the Cyclone's air suspension has been replaced with period-correct steel springs.
It's a chilly morning as I climb in, with the bubble top stowed in the trunk. The long, stainless-steel-encrusted steering column puts the St. Christopher medal in my gut, like the driving position in a '50s Formula 1 racer. The seat cushion is long, and the seatback seems short.
'This was done for Harley Earl's proportions,' Welburn says of the seating position. He had long legs and a short torso. I need to stretch my right leg to reach the throttle and brake pedals, both hinged on the floor.
The dashboard mixes 1959 state-of-the-art features with future tech that never happened. Proximity and stopping distance gauges atop the center stack were for the nose-cone sensors. Other gauges cover manifold pressure, fuel, amps, an 8000-rpm tachometer, a 200-mph speedometer, and the biggest surprise, a Breitling clock. The odometer shows just 904 miles and, aircraft-style, 14,730.9 hours.
If the proposed transaxle ever was hooked up, my limited drive on the grounds of the Eero Saarinen-designed GM Tech Center and design studios doesn't reveal any more than three Hydramatic gears.
There's a public address system, to speak with pedestrians when the canopy is up.
The XP-74 would make a good rainy-day parade car. There are seek/scan AM radio controls forward of the center armrest, a Chrysler Turbine-like grooved cylindrical transmission-hump cover, and a grab handle where the glovebox should be. The driver's door has a mail slot for toll roads, for when the bubbletop is up. I start with it down.
'If you smell raw gas, there's no air cleaner,' the handler, a longtime GM employee, warns. It turns over quickly, with a twist of the key. Raw gas? The top is down, and the dual exhaust pipes open between the doors and front wheels. I'm more concerned with burnt gas blowing into the cockpit. No wonder it has just 904 miles. The 390-cube V-8 has oodles of torque, and my tip-ins are too heavy at first, prompting considerable squat from the soft rear suspension. The steering is as you'd expect: Lean back in the seat, choose a convenient finger, and use it to make turns. It turns in quickly, though, and is exceedingly easy to maneuver for a two-seater that's 5.3 inches longer than a modern CTS. After all, the wheelbase isn't much longer than its dash-to-axle ratio.
One-two shifts are smoother than I'd expect from an aging Hydramatic. The car can get up and go, even if not to 200 mph, and I'm wishing I could take it out, unlicensed, on the freeway. Hold on, St. Christopher, here's an idea. If the Cyclone isn't licensed for public roads, let me fly it.
The handler hesitates to raise the bubble top. He does it with the help of our photographer. It was supposed to have a power top, but the two must carefully lift it out of the trunk, then slide it up and over me as I'm in the driver seat. Getting in and out through the low sliding door with the top up requires the kind of limbo dance I could manage better back in the early '60s.
Still…whoa! Top-up is cool. The Cadillac Cyclone isn't just the bridge between Earl and Mitchell. It's the bridge between the cars we got and the flying cars we were promised. With the 360-degree view just slightly yellowed, the bubble-top Cyclone feels like a fighter jet ready to accompany Slim Pickens' B-52, flying under the radar in 'Dr. Strangelove.' It's an aerospace-future version of the cars I remember from my childhood, though a notch or three higher up the Sloan price ladder. If I could drive it faster, I'd catch and shoot down that Soviet MiG, or at least pass George Jetson's family car.
'I think of this car as a concept, up there on that angel hair,' Welburn says. 'Look at the shape of the windshield. It's so much newer than anything else from its time.'
Welburn then reveals why he didn't want me to drive it: He never has.
'I worry that driving it will take a little bit of the magic.' Spoken like a car designer. It's about the way it looks. There's nothing in a late '50s Cadillac's driving dynamics that will add to the car's cachet.
Similarly, you've got to love Earl and Mitchell for what they did, not who they were. Take Mitchell. As our photographer clicks his last shots of the Cyclone behind GM's Design Dome and the sun begins to set, the GM car handler recalls the day he retrieved Bill Mitchell's Ferrari-powered 1971 Pontiac Firebird Pegasus [Motor Trend Classic, March/April 2006] from Mitchell's garage after he retired in 1977.
'It took me days to get all the NRA stickers off the car. Mr. Mitchell loved his guns.' The handler pauses, then attempts to make the firearm obsession benign. 'He collected guns.'
Welburn, the handler, and I are standing side by side, watching David Freers shoot photos as the sun lowers behind the Design Dome. The brief silence is long enough to consider all the car guys I know who also love guns. Just as I begin to wonder about my car-guy credentials because I've never fired a gun, Welburn breaks the silence in his low, soft voice, offering a better second obsession, one Tom Waits and St. Christopher might appreciate. One exceedingly appropriate for the style and lifestyle the XP-74 exudes.
'I don't collect guns …' Another long pause. 'I collect cocktail shakers.'