What do you call a vehicle with 5 wheels?

A five-wheeled vehicle is most commonly called a “pentacycle” when it’s human-powered, and more generally described as a “five-wheeled vehicle.” The informal term “quinticycle” also appears, though it’s less common. In automotive contexts there’s no single standardized name; engineers and journalists typically just say “five-wheeled.” Note that “fifth wheel” usually refers to a trailer hitch, not an actual fifth road wheel.

What the terminology means—and when to use it

In transportation and design, naming conventions vary by propulsion and context. Human-powered designs (bicycles and their derivatives) traditionally take the suffix “-cycle,” while motor vehicles are more often described by wheel count in plain language. Understanding these conventions helps avoid confusion with similarly named hardware like the “fifth wheel” hitch used in trucking.

Etymology and usage

“Pentacycle” pairs the Greek penta- (five) with -cycle (wheel/circle), aligning with long-standing cycle nomenclature (unicycle, bicycle, tricycle, quadracycle). “Quinticycle” uses the Latin-derived quinti-; it’s understandable but less standard. In motor-vehicle writing, you’ll typically see “a five-wheeled car/robot/cart,” because the field lacks a canonical single-word label.

Notable examples and where you’ll encounter five wheels

Although uncommon, five-wheeled designs appear in specific niches, historical experiments, and specialty platforms. The following items illustrate how and why designers have used five wheels.

• Humber Pentacycle (1882): A British human-powered machine with a large central driving wheel and four small outrigger wheels for stability, used by the Post Office for telegram delivery in the late 19th century.
• Camera and industrial dollies: Some modular dollies and carts add a fifth caster to improve tracking stability over seams or when carrying asymmetric loads.
• Wheelchairs with anti-tip casters: Certain active or power wheelchair setups employ a small fifth wheel at the rear as an anti-tip device.
• Robotics platforms: Mobile robots occasionally use a fifth wheel (often an omni or caster) to stabilize a four-wheel drive layout or support heavy payloads without complex suspension.
• Drag racing “wheelie” devices: While not road wheels in the usual sense, some drag bikes and cars use small auxiliary wheels to prevent flipping—functionally adding a fifth contact point.

Taken together, these examples show that five-wheel configurations are typically purpose-built for stability, weight distribution, or maneuverability rather than general consumer transport.

Common misconceptions to avoid

Because “fifth wheel” has multiple meanings in transportation, it’s easy to talk past one another. Here are frequent points of confusion and how to interpret them correctly.

• “Fifth wheel” in trucking is a hitch plate, not a fifth road wheel. A semi-tractor still runs on its standard tire count; the “fifth wheel” is the coupling device.
• A spare tire doesn’t make a vehicle “five-wheeled.” Wheel count refers to wheels in contact with the road during normal operation.
• Training wheels aren’t the same as dedicated five-wheel designs. Bicycles with two training wheels temporarily have four wheels; a single stabilizer would make it three, not five.
• There’s no standard automotive term like “pentacar.” Most sources simply write “five-wheeled car/vehicle.”

Keeping these distinctions straight ensures the term you choose conveys the intended configuration rather than a hitch type or accessory.

Why five wheels at all?

Designers sometimes choose five wheels to balance competing goals—stability, packaging, and simplicity. A central drive with four outriggers can stabilize a tall or narrow vehicle without adding suspension complexity; a single stabilizer wheel can support a heavy payload while keeping turning friction low. The trade-off is added weight, cost, and mechanical complexity compared with the ubiquitous three- or four-wheel layouts.

Summary

The most accepted term for a five-wheeled, human-powered vehicle is “pentacycle,” while in broader contexts it’s best described plainly as a “five-wheeled vehicle.” “Quinticycle” is understandable but less standard. Historically rare, five-wheel designs appear where stability or load support is paramount, and the phrase “fifth wheel” usually refers to a trailer hitch—not an extra road wheel.

What type of vehicle is a 5th wheel?

A fifth wheel is a type of RV that connects to a pickup truck via a hitch in the truck bed, offering stability and spacious living. This article will cover the features, types, pros, and cons of fifth wheels, helping you understand why they’re a popular choice among RV enthusiasts.

What is a 5th wheel vs. gooseneck?

Gooseneck hitches are less invasive, relatively less expensive and make it easier to free up the truck bed with smaller, lighter-weight components. Comparatively, 5th wheel hitches generally offer smoother, quieter, more stable towing and are available in a range of weight capacities to suit a variety of trucks.

Why are 5th wheels called that?

History of the Fifth Wheel Design
But why is it called a fifth wheel? The name actually comes from the company that first utilized the hitch in the early 1900s. The Martin’s Fifth Wheel Company named their device after the round shape of the hitch. Hence, the hitch itself is the “fifth wheel.”

What is a vehicle with 5 wheels called?

Fifth wheels are a type of towable RV. They are large, spacious and towed by a truck.