In hindsight, the GMC Motorhome is an incredible, improbable thing. Campers and RVs and Motorhomes or whatever you want to call those drivable houses-on-wheels have always been the domain of smaller, lower-tech specialist companies as opposed to major automakers, which is why so many RVs are built like construction company office trailers bolted to a truck chassis. The GMC Motorhome was different, enjoying the full engineering might of GM to make something really special. Too bad it died in 1978. Well, in reality it died in 1978, but in the mind of The Bishop, our closeted auto designer currently toiling in another field, the GMC Motorhome was reborn in the 1980s! Let’s enter this glorious fever dream and delight at what could have been if it were all fortunate enough to live beyond the damp confines of The Bishop’s head.
Before that, though, let’s just go over one more time why the original GMC Motorhome was such a big deal. Other than perhaps Volkswagen with its Westfalia-camperified Type 2 Microbuses, no major automaker was selling its own, in-house-designed RVs or motorhomes, certainly not ones built on a purpose-built chassis. But that’s exactly what GM did.
The state of RV design in the early 1970s was crude, even the good ones like Winnebagos: corrugated metal, pink insulation, boxy, curve-less designs on heavy chassis. They were charming, but crude as hell.
GM took a clean-sheet approach, and attempted to make something that was better than driving a giant shed, and at least attempted some degree of aerodynamics. The company took its tidy front-wheel drive V8 powertrain from the Oldsmobile Toronado and Cadillac Eldorado and plopped it down in a bespoke chassis with a nice low floor, no driveshaft, and plenty of room for fuel, fresh water, and disgusting water tanks, and then dropped on that an extruded aluminum frame covered with fiberglass and aluminum body panels.
The rear had twin axles with independent air suspension, and the result was something roomy and comfortable and not horrible to drive. Ads of the era emphasized this a lot:
When GM engineers really put their collective minds to something, they can do amazing things, even if they often screw them up later. The Motorhome was an example of this, with GM developing what was arguably the finest commercially-available vehicle that you could drive, sleep, and shit in.
Also, you may remember the GMC Motorhome played a role in the 1981 Bill Murray/Harold Ramis army-comedy Stripes as a fictional Urban Assault Vehicle:
Anyway, all of this is to say that the GMC Motorhome was a remarkable RV milestone, and yet it only lasted five years, from 1973 to 1978. The discontinuation of the Toronado and its V8 FWD drivetrain was a factor, as was the fuel crisis.
The story in our stupid reality ends there. But, now we dive into the gooey depths of the Bishop-brain, where we discover that, holy crap, GM resurrected the Motorhome project in the late 1980s, and had an all-new GMC Motorhome by 1987!
Here’s what it (could have) looked like:
I bet the first thing you’re noticing is that, like the original 1973 Motorhome, this is a three-axle design, only here the twin axles are up front. What the hell? Well, there’s actually a reason for this, and it’s not unheard of: The British Bedford VAL bus used such a layout, as well as some Mack and GMC tractor trailers.
This layout is referred to as the “Chinese Six” layout, and while I was afraid the origin of that term might be overtly racist, it seems to just be because it’s reversed from the expected, in the sense that China was thought of as being on the other side of the world, or whatever. I hope it’s not racist, at least.
Here’s how The Bishop explains the logic behind the double front axles:
“This approach allows for narrower, smaller front wheels for a lower floor, as well as better handling, redundant tires for a blowout, and tighter turning circle. Different sized wheels, different spare tires needed? Yes, but the advantage here is the smaller-than-motorhome sized front tires used could be more readily available, i.e. the size of pickup/van tires…”
So, with all those axles up front, where is the engine going to go? Well, in 1987’s Motorhome, that’s reversed, too, and even weirder, in some ways:
The 1987 model would still have the air suspension of the 1973 design, but would ditch the FWD system for a rear engine. …better for towing and the elevated power barn area won’t matter since it’s under the bedroom in back. Likely it would be a new generation Cadillac V8 FWD system stuck in back…but would that be enough power? Did they have a transaxle strong enough, and if not would GM really invest in special transaxles for as small a run as these might be (at least in there terms of ‘small run’)? What if, to keep development costs lower, you had two 2.8 or 3.3 liter V6 motors in back…one for each wheel so no differential? This mock V12 would still probably get better gas mileage than the Cadillac 8.2 liter of the original.
Yes, twin engines! Two V6s are pushing this thing. I suspect that these V6s, normally used in a transverse configuration in other cars, could use existing transverse transaxles, with the inner axle shafts of each engine connected together? This could allow for dynamic engine de-activation to save fuel on highway trips, maybe?
Anyway, here’s a diagram:
Let’s look carefully at this cutaway, because it’s full of great ideas. The radiators are mounted in pods on each side, and flanked by slide-out cargo trays/drawers, though I do wonder if the Bishop may need to sacrifice some of that storage for water tanks? Maybe not.
The hump created by the engines is well-hidden under the big double bed at the rear, and, for an RV, there’s a remarkably large front passenger compartment. As The Bishop explains:
The extra space from the small wheels allows for a spacious front compartment. I’ve always hated that a great many RVs offer good seating for driver and passenger, but other passengers can’t ride in it like a regular car and enjoy the view with Mom and Dad like they can in the Caprice wagon they left parked at home. It’s also dangerous as fuck to sit at some dinette or lie on a bed while going 70MPH (Metallica’s Cliff Burton comes to mind). The journey is just as important as the destination and I wanted to make this thing offer driver and passengers as close to a car-like experience as possible. Consequently, this would feature two rows of seating that is forward facing for while the RV is in motion..MUCH safer and creating a better travel experience.
I mean, when I crossed the country with my family in an old RV, one of the best parts (for them) was sitting in the living-room-like environment of the RV, but, sure, that’s not really all that safe, so I get this.
The Bishop has really thought through the potential of this front cab-like section, and with proper Captain’s Chairs-type of seating, this can be a true multi-purpose area:
Lots of clever swiveling and folding going on here, which is what we all want to see most in fictional RV designs, right? It’s great.
“This big front area would become a living room when the thing is parked by rotating the front seats around, or all seats can face forwards to watch TV (either a giant CRT or maybe a projector screen at the windshield). Or, this space can become another sleeping area by folding down the ‘back seat’ couch (curtains could separate this area from the dining/kitchen space to create a private ‘bedroom’). Note that I stole a bit from the Imperial Mobile Director by having a removable table that also has padding when folded open to create an extra passenger filler for the rear seats.”
The Bishop was also inspired by 1980s GM’s affinity for dashboard CRT displays, as seen in the Buick Riviera, so he’s specified a dashboard for the Motorhome absolutely slathered in cathode ray tubes:
Now, rear-view camera systems in RVs that used little black-and-white CRTs were a thing for a while, so that part isn’t terribly unusual, but a multiple CRT-instrument cluster is exotic, with the only car I can think of that used such a setup being an Aston Martin Lagonda. Still, with GM’s experience in mass-producing automotive CRT displays in its Buicks, I don’t see why the company couldn’t have pulled this off.
If there’s one thing The Bishop understands, it’s that the work he does for us here is fundamentally entertainment, and you’ve got to have some crowd-pleasers in there. That’s why this is part of his ’87 GMC Motorhome design:
Since everyone seems to expect me to draw some sliding/folding shit, it must be done. How about at the back, under the spare tire compartment, you have a pocket for up to three slide-out electric GM Skooterz – basically Sinclair C5s on steroids with which to terrorize other campers with or go get beer at the general store on and crash (class action lawsuit here). You can sit or stand on them (the seat folds up), and they work as JetSkis on water, too…well, no, they don’t…but it’d be a lot cooler if they did. It only has one front wheel and RWD but GM would still have been able to dial in some torque steer….I crack myself up.
Oh, and The Bishop knows he needs to please me, too, so we get this detail as well:
Those are 1987 base model Firebird taillights on the motorhome.
It’s a shame GMC got out of the motorhome business, because they had such a fantastic start, and, as The Bishop’s alternate reality makes pretty plain here, they could have pushed it so much further. Today’s motorhomes aren’t particularly sleek or advanced or clever, at least not at the levels that most humans can afford, which makes me think there’s still an unfilled hole GM could fill, if they wanted.
But I’m not going to hold my breath. Best to just live in the fantasy world crafted by the fertile mind and pen of our own Bishop of Fictional Vehicles.
As long as we’re daydreaming…I never could understand why no one has electrified the GMC Motorhome on the Railroad Locomotive pattern – replace the Olds FWD drivetrain with a small Diesel that runs BioDiesel or even re-processed vegetable oil, that turns a generator which charges a battery pack nestled between the frame rails (a la GM’s Skateboard platform), which supplies electricity to in-wheel motors. Since this is an updated daydream, let’s make the the dashboard a Glass Cockpit, including camera fed mirror displays.
If anyone is wondering why GMC didn’t continue with its Motorhome after the passenger E-platform was downsized in 1979, it had to do with the Unified Powerplant Package® (UPP®) being redesigned and downsized for smaller and lighter vehicles. GMC used the 455 then 403 Oldsmobile V8 and beefy THM425 gearbox with wider roller chain. For 1979, UPP® was downsized to Oldsmobile 307/350 and Cadillac 368 V8s and wimpy THM325. Neither was up to snuff for heavy vehicle. On the other hand, why couldn’t GMC continue the smaller production of 403, Cadillac 425 (which 368 was based on), or even GMC’s own truck V8 and THM425 for a several more years, hmm?
Anyway, my family were this close in hiring the GMC Motorhome for our first American road trip with RV in 1977. The hire cost was too high for my father’s liking so he took cheaper and slightly shorter Pace Arrow. “Penny wise, pound foolish” would be the slogan here. The aerodynamically inefficient Pace Arrow consumed much more fuel than GMC Motorhome would. My father ended up paying way more for the fuel, negating the initial cost saving. The family of my classmate’s had one, and I rode in it a several times on the shorter road trips through Texas. It was the most comfortable RV: almost like riding Citroën CX.
I disagree. The GMC motorhome was at its best being FWD with the tandem single wheel rear axles and air suspension.
I’d argue it’s the best full size motorhome ever mass produced.
The small rear engined ‘pusher’ RVs didn’t seem to catch on. The other stick/diesel 20 foot RV was the Winnebago LeSharo , a euro Renault Trafic van based FWD design. It used the whole front passenger compartment of the Renault but added a shovel nose with Buick Skylark headlights. Sold better than the Vixen despite only 66HP. This was replaced by the much more successful VR6 powered Eurovan nosed Rialto.
My grandparents had one of the original GMC RVs. First big trip I remember as a kid was caravaning out to Rapid City for a week or two in the early 80s with them in that high-tech, sleek seeming machine and us in our standard Winnebago.