Fifty Years Ago, GM Built The Motorhome Of The Future. Here’s Why It’s Still One Of The Greats

Because I’m a goth dandy, I like to be comfortable when I travel. Long distance flights usually require the application of alcohol, headphones, and a few good movies of my own choosing. Upon arriving at the hotel, I don’t need obsequious service – a cocktail bar, the ability to obtain a decent cup of coffee, and a large bed with a lot of pillows are my pre-booking prerequisites, and a good post-arrival shower helps when hopping time zones. In other words, I like to be comfortable, clean, and presentable. This is why I have never really got on with camping.

Camping baffles me. It’s like a holiday with extra aggravation and less comfort. You spend ages sticking things in the ground, erecting tents, setting equipment up, and generally faffing about just so you can drink something resembling coffee from a tin cup. Once set up in the great outdoors, there are insects that want to bite you and wild animals that want to eat you. A lot of this palaver can be minimized by using a caravan or an RV, but out of all the aluminum boxes Miss Mercedes has towed behind her broken panzers, none of them have so much as a drinks cabinet.

I have camped in the past. A couple of years ago I soiled the back seats of my Ferrari with tents and sleeping bags to go to the Le Mans Classic and will do so again this July. I’m an insufferably pretentious idiot, so imagine my horror at discovering my camping stove struggled to boil a Moka coffee pot. What might change my mind about all this is a wheeled home away from home that allows me to travel with dignity. An RV with a sense of style that doesn’t drive like a waterbed and with enough design credibility and comfort to make me rethink my anti-camping stance. Fifty years ago such a thing existed: the GMC Motorhome.

It Started With Oldsmobile

The GMC Motorhome was a ground-up rethink of how to design and build a recreational vehicle with none of the inherent compromises present in mobile homes available up to that point. Its revolutionary layout and construction encouraged GM to explore using the platform for a wide range of commercial uses. It wasn’t some off-the-books skunkworks project – the Motorhome had the full backing of the board and all the resources of GM design behind it. Never missing an opportunity to miss an opportunity, GM pulled the plug after six years just as the RV market was about to explode.

The GMC Motorhome story begins with the Unitized Power Package (UPP) that debuted on the 1966 Oldsmobile Toronado. At the time, each GM division still operated independently with its own engineering staff, and Oldsmobile’s intention for the UPP was to create a lower-cost front-wheel drive car. America’s last front wheel drive car had been the 1937 Cord, so working out how to package a V8 engine with an automatic transmission to drive the front wheels meant the project spiraled in development time and expense, and the UPP initially ended up in high-end models. The November 1965 issue of Car and Driver was particularly effusive in its praise of the Toronado, writing:

“The Oldsmobile Toronado is a beautifully engineered product that indicates a spare-no-expense attitude from conception to completion. The entire design is uniquely free of most of the traditional Detroit engineering prejudices and the only area which indicates anything less than utter open-mindedness is the retention of drum brakes.”

After a year of proving its worth in the nose of the Toronado, the UPP was mated to Cadillac’s 429cu in V8 and installed in the new 1967 Eldorado.

The advantage the UPP gave these big yachts was not just technological bragging rights over traditional rear-drive sedans. Tires weren’t so great back in the sixties, so having the weight of the engine over the driven wheels gave significantly more grip in low traction situations. With no transmission tunnel to factor into new front-drive designs, the passenger cabin could be bigger, and crucially from an aesthetic point of view, lower. No bulky live axle meant a larger trunk and improved ride quality. These positive attributes would be instrumental when it came to designing and manufacturing an entirely new kind of RV.

The Nascent RV Market

Our very own Mercedes Streeter is the resident RV expert around here, and lest she slip a rusty screwdriver between my ribs, here’s an article she wrote that is an excellent primer on motorhome history. When Winnebago started out, their initial offerings were aluminum houses on wheels. This 1968 Winnebago F17 (for its 17-foot length) doesn’t have a single curve on it – Winnebago tried to make this a selling point by noting it maximized interior volume. Some enterprising individuals tried to make softer, more aerodynamic-looking vehicles, but nonetheless all these RVs had one big compromise in common: they were bolted on top of existing commercial truck chassis.

Building on top of a truck chassis not only meant a higher floor, it also meant a crunching ride and relatively poor handling due to the higher center of gravity. On top of all that, traditional body-on-frame construction was not ideal for fragile interior fixtures and fittings. Finally, you need the cooperation of a manufacturer willing to sell you a complete chassis and engine package. None of this was lost on RV pioneer John Hall, the stepson of Airstream founder Wally Byam. In 1968, Hall took the UPP and mated it to an aluminum body with a bespoke chassis to create the first Revcon motorhome. According to the website Tin Can Tourists:

“In 1968, the first Revcons were built. They included aircraft aluminum monocoque body construction, and a custom built chassis with Oldsmobile Toronado front wheel drive. The lightweight, low profile and front wheel drive made the Revcon handle as well as any American car of the day, quite a feat for a 12,000 pound motor home. It certainly helped the fuel economy, consistently 2 to 4 MPG higher than the competition. The innovation didn’t end with the drivetrain and body, Revcon took it to the interior as well. Lightweight materials were used throughout. Cabinets were constructed of aluminum honeycomb core sandwiched between 2 thin layers of Formica. Not only did this save weight, it was much more durable than the plastic or pressboard cabinets that were typical of the era and are still the industry standard today.”

The Revcon proved that the idea of advanced construction and lower ride height with front wheel drive gave noticeable improvements in ride and handling and gas mileage. The problem was the Revcon’s under-the-skin revolution was undermined by its unsophisticated and dumpy appearance. Even though they were lighter than other RVs of the day, Revcons didn’t look it. The vehicle sat heavily on inset wheels, and despite having flush skin with rounded edges, it seems little consideration was given to aerodynamic efficiency or aesthetic appeal. Thanks to the expanding market, there was still an opportunity for a motor home that holistically combined advances in construction and powertrain in a vehicle where the external appearance represented the same leap forward. There doesn’t appear to be any direct connection between the original Revco and the new GM RV other than the fact they both used the UPP, but it’s not uncommon for different manufacturers to have similar ideas because they are looking at the same problems.

General Motors Wants A New Halo Vehicle

Under the supervision of GM Vice President Martin Caserio who also headed the GMC Truck and Coach division, the new vehicle was to be “the Chevrolet of motorhomes” – something designed from the ground up with the full resources of the mighty GM design staff behind it. GM began by comparing the layouts and floor plans of existing RVs and began by building full-size interior bucks in the basement of the Tech Center. This might seem like overkill, but designers and engineers need something physical they can touch, see, and sit in to try out. It helps them understand exactly what problems they might encounter, especially if it’s a type of vehicle they have not designed before.

GM was determined that the TVS-4 (Travel Vehicle Streamlined) as it was first known would have a comfortable ride. To that end, the  TVS-4 featured a novel tandem twin-wheel arrangement at the rear. Each pair of rear wheels was connected by a railway-style bogie and suspended by a hydraulic spring, pressurized via the power steering pump. This eliminated the need for a rear axle spanning the chassis, and wheel well intrusion into the interior was kept to a minimum, further liberating space. A test chassis with a fake bus body on top named the Pie Wagon was used to convince GM executives to approve the project. This also had the benefit of throwing spy photographers off the scent, as rumors were already circulating that GM might be turning its attention to the increasingly lucrative leisure vehicle market.

With serious design work underway by 1970, the exterior team got to work. Michael Lathers was in charge, and his team soon had walls of sketches, and according to the GMC Motorhomes International website three or four exterior sketches progressed to 1/8 scale clay models. Today, the normal scale for smaller theme clays (used to decide what to take forward to full-size clay) would be 1/4 or 1/5 scale to keep the model to a reasonable size.,

The one full-size model that was completed was probably the largest clay the GM studio ever made. A smaller 1/16 scale sculpt was created for wind tunnel testing, and eventually achieved a Cd of 0.31. Once the full-size clay was completed and signed off, plaster molds were taken directly from the surface to make prototype fiberglass body panels. These were then used to draft the technical drawings for the actual tooling. The production body used an aluminum frame with fiberglass panels bonded directly to it above the belt line, with aluminum construction below the belt line. This made the final shell incredibly strong and light for its size.

While the exterior design was progressing, the usual GM rigmarole was taking place elsewhere. The hydraulic suspension system went overdue and was over budget. According to Silodrome, Firestone came through in 1971 with a simpler compressor-driven air suspension system to replace the hydraulics. Chevrolet had wanted to keep the motorhome as a second halo model alongside the Corvette, against the wishes of GMC. Because it was projected to weigh over 10,500 lbs, GM management decided TVS was a better fit for the commercial vehicles division. Again according to Silodrome, some at GMC favored a cheaper, more traditional slab-sided motor home; fortuitously Alex Mair took over from Caserio in 1973 and decreed the TVS wasn’t going a Chevrolet of motor homes: now it would be the Cadillac of motor homes, and the TVS’s status as a showcase halo product was assured.

For the interior design, GM had a dedicated team working on different layouts. They wanted the furniture and fittings to represent contemporary tastes in interior décor, further demonstrating a commitment to ensuring the TVS was a complete, well-considered design inside and out. To that end, House and Garden magazine consulted on various interior décor finishes. According to GMC Motorhomes International (GMCMI), in one meeting GM president Ed Cole even went as far as to suggest bright, attractive colors should be used –  pointing to the orange of chief engineer Wally Edwards’ tie.

The prototype GMC Motorhome was revealed to the press and public at the enormous 1972 U.S International Transportation Exposition – Transpo ’72. According to GMCMI:

Martin J. Caserio, General Motors vice president and general manager of GMC Truck & Coach, said the motor home prototype is representative of GMC’s long-term development program for a new chassis and body adaptable to a variety of purposes. “The 26-foot motor home to be exhibited at Transpo is the first application of the new GMC chassis and body design,” he reported.

Caserio said development work is continuing for other potential applications, such as a small bus for metropolitan transit operations, an ambulance and rescue vehicle, a mobile medical clinic, a vehicle for physically-handicapped riders, an airport bus and a display or service van. Many GM cars and trucks were on display there as well as the tan colored 26-foot Motor Home. The exterior was rather plain with no stripes or trim. In a brochure it was described as “An experimental prototype of GMC Truck & Coach Division’s complete motor home, to be marketed in early 1973″. The GM display was still labeled as a ‘Multi Purpose Vehicle” although all efforts were now focused on developing and producing a Motor Home.

It Wasn’t Just Going To Be A Motor Home

The GM team had such faith in the TVS that they decided to not only offer the motorhome fully fitted out in two lengths – 23 feet and a 26-footer — but also offer empty Trans Mode models to existing RV builders for them to add to their line of existing conversions – although these ‘unofficial’ motor homes were only built in small numbers.

GM had much bigger plans for the Trans Mode. Its structure was deliberately designed with a removable body ‘cap’ on the rear. Commercial vehicle builders could simply unbolt the end of the Trans Mode, fit it out as they liked, then simply bolt the end cap back on. GM created sales documents listing possible adaptations to the basic Trans Mode box including executive long distance transport, mobile laboratories, bookmobiles, mobile corporate showrooms, mobile classrooms, crime-prevention vehicles, bloodmobiles, and even horse boxes. If you can imagine a business use for a smooth-riding and quiet commercial vehicle with a voluminous and infinitely adaptable interior, GM either sketched it or built it.

Production began in late 1972 – the main vehicle was built at GM assembly plant no. 3 in Pontiac, Michigan, and interior construction was subcontracted out to Gemini, a new company set up by PRF Industries which already had experience building RVs.

There was the usual bewildering choice of interior layouts and options, and the base price was $13,569 for the 23’ model and $14,596 for the 26’. GMCMI says GM anticipated an annual volume of 8,000 units a year and expected to take 10% of the market. Even though it was a low-volume, high-priced product, the motor home sold in reasonable numbers considering the pressures all the automotive industry was facing at the time. Despite this production lasted only six brief years until 1978, and a total of 9715 Motorhomes and 3206 Trans Modes were built. The official reason GM gave for ending production was the space was needed at the Pontiac plant for more profitable trucks, but we now know GM executives were not enamored with expensive to build, design led vehicles and were gearing up to take a much more cynical approach to the business of selling cars. A low volume high image product was a poor fit in a company designed to stamp out vehicles by the hundred thousand.

How The GMC Demonstrates The Importance Of The Design Process

In 1973 the GMC Motorhome must have looked like a spaceship. In a way, that’s exactly what it was – a vehicle to transport you from one location to another in ease and comfort. GM took the design of the Motorhome just as seriously as they did any of their cars – and it shows in the refined, considered appearance.

The wrap around glazing gave the driver confidence on the road – opening up the driver’s view out for great visibility. The progressive and modern exterior reflected the fact that the GMC was unlike any other van on the road – and it didn’t drive like one either. It was lighter, more spacious and more refined than any of its competitors. And the beauty of it for paying customers was it was built by GM, not some company they’d never heard of advertising in classified adverts of a small town newspaper.

One of the reasons I wanted to discuss the GMC is because it starkly illustrates what car designers actually do and contribute to the development of a successful vehicle. Look at the RVs currently available. Large ones are McMansions on wheels – tackily trimmed and garishly decorated. The pioneering form factor of the GMC – lower to the ground and front-wheel drive, only exists in smaller RVs today thanks to the proliferation of Euro FWD van based conversions. The rest are just overlanding boxes crudely bolted on a truck chassis.

Quite often, any vehicles (not just RVs) from smaller companies look terrible because they don’t have the resources to employ professional designers. They might see it as an unnecessary expense, a drag on time to market or just don’t understand what a designer can contribute beyond making things look pretty. Something I learned a long time ago is even in vehicle categories where you think aesthetics don’t really matter, they absolutely do. Given two products of similar capability and feature set, customers will always choose the one that appeals to them visually.

One of the lines GM used in advertising the Motorhome was “our goal was to make getting there as much fun as being there.” To steal a phrase beloved of UI/UX designers they wanted to make camping and road trips as frictionless as possible. The GMC Motorhome website estimates that of the 12,000 or so built, between 8-9000 are still registered. Revco even copied the basic exterior design for their later models. The most cursory of internet searches confirms these glorious RVs still have a dedicated and enthusiastic following, a testament to their rightness fifty years later. With updates to the lighting, grill and bumpers you could imagine the GMC Motorhome being sold today –  it would still look incredibly fresh and modern, because brilliant design transcends time in both form and function.

[Mercedes’ Note: Part of what’s so fascinating about the GMC Motorhome is that GM’s designers and engineers basically found the ideal medium motorhome formula. The coach was low to the ground, comfortable, had huge windows, unmatched style, and had a build quality that too many RVs from today cannot match. It’s not surprising that some people would rather spend a half-million dollars modernizing an old GMC Motorhome instead of buying a new coach.

This piece makes me wonder what modern Class A RVs would be like if they were penned by car designers. We sort of see a glimpse of that with the new Lightship and Pebble trailers, which were designed by Tesla and Rivian alum. – MS]

Car design isn’t something that only takes place when the sun is shining. You need to view models outside in natural light all year round. When GM designers wanted something they could sit in to view models outside during the harsh Detroit winters, guess what they used.

Once again my sincerest thanks to the GM Heritage Archive who dug into their records for these images. Also thank you to The Bishop for additional research – keep your friends close and your enemies closer. Finally special thanks to resident camping masochist Miss Mercedes for fact checking this piece for me. 

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