The GMC Motorhome: A Classic With a Surprisingly Long Dipstick
There are certain vehicles that consistently capture the attention of the Autopian staff, and the GMC Motorhome is definitely one of them. These vehicles, including the Citroën SMs, Toyota Centurys, Yugos, and BMW i3, always seem to spark a conversation.
Even our normally stoic British designer, Adrian, shares an unusual fondness for the GMC Motorhome. And it’s easy to understand why! These things were exceptionally cool, pushing the boundaries of motorhome design and construction in a way that, sadly, General Motors eventually abandoned. It’s another classic example of GM having a great idea and then letting it die. Yet, we still love them and its easy to see why – a full aluminum/fiberglass body that resembles a land-zeppelin, a FWD drivetrain from the Toronado, and some groovy 70s interiors; the GMC Motorhome has it all.

For anyone unfamiliar, here’s a good introductory video that might help provide some context:
The Surprisingly Long Dipstick
Now, let’s get to the primary point of this article. Take a look at these diagrams:

Notice how the Toronado V8 engine sits in what GM referred to as the Unitized Power Package? You can see that the engine is located just over the front axle. Because it’s located under the floor, getting to it can be difficult. GM thoughtfully included access panels in the front to access the washer fluid, brake fluid, and, yes, the oil for both filling and checking.
Now, consider the distance between the front of the motorhome and the engine’s actual location in the cutaway diagram. That leads us to this:

That’s quite a long dipstick! The thing just kept coming, a bit like a clown pulling a seemingly endless chain of colorful handkerchiefs from his pocket.
This dipstick is 54.25 inches long, which is around four and a half feet, or roughly the same height as my mother. It’s an interesting quirk. Compared to the small-engine dipsticks I’m used to, this one seems almost absurd the length is entirely normal for certain delivery vehicles.
For comparison, here’s a 55-inch dipstick that fits a Chevy P30 Step Van, one of the most common delivery box vans around.
Even longer dipsticks exist in the world of large-scale ocean liner engines and large oil tanks. These use specialized tools called “oil-gauging tape measures.” They can reach about 50 feet in length.
What a world, right?