How Many Wheels Are On A 18 Wheeler? Why Is It Called So?

Robert Herrera-COR-Wheels

By Robert Herrera

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When it comes to commercial trucks, the term “18 wheeler” is a commonly used phrase. This term describes the most common type of commercial truck and trailer combination, which consists of 18 wheels. But have you ever stopped to wonder why these massive vehicles need so many wheels? Let’s find out the answer and more information about eighteen-wheelers!

How Many Wheels Does An 18 Wheeler Have?

Typically, a wheeler’s number of wheels and rims match up. This means an 18-wheeler has 18 rims with 18 tires. Still, notice that this does not apply to every heavy-duty tractor.

Not all 18-wheelers are created equal. Some semi-trucks may have additional rear drive axles or specialized configurations depending on the type of cargo trailer they are designed to haul. 

18 wheeler

For example, a tanker truck may have a technical axle configuration to help prevent the liquid cargo from sloshing around during transport or on harsh road conditions.

How Long Is An 18 Wheeler?

Generally, the maximum legal length for a commercial truck and standard trailer in the United States is 80 feet. But the length of an 18-wheeler can differ in each type of truck and trailer being used.

This includes the tractor (the front part of the truck containing the engine and driver’s cab) and the trailer (the cargo-carrying component attached to the tractor).

However, some states have different laws and regulations regarding commercial vehicle lengths, so the exact size of an 18-wheeler can vary depending on where you are in the country.

In addition, there are different types of trailers that can be attached to an 18-wheeler, such as flatbeds, tankers, and refrigerated trailers, each with their own specific length and dimensions.

Why Is It Called An 18 Wheeler?

The term “18-wheeler” refers to a specific type of commercial truck and trailer combination. The name comes from the number of wheels on the rigid vehicle, with each wheel representing one of the 18 total wheels.

Typically, an 18 wheeler consists of a tractor unit with two lift axles and four extra wheels and a trailer with two to three axles and four to six trailer wheels. 

This term is a colloquialism that has become popular in the United States and is widely used in the trucking industry. It is also sometimes referred to as a semi-trailer truck or a tractor-trailer.

Are More Wheelers Better For Trucks?

More Wheelers Better For Trucks

More wheelers are better for towing/loading, though this is not absolutely necessary. The most straightforward explanation is that a semi-trailer can carry more weight the more axles it has.

However, a wheeler truck becomes less maneuverable the more axles it has. Adding rolling resistance from additional trailer axles reduces a vehicle’s efficiency and might result in other operating expenses due to tolls. Bigger vehicle tires are expensive and need to be replaced as more tires are used.

Frequently Asked Questions

Do Trucks Have 16 Or 18 Wheels?

The number of wheels can vary depending on the specific type of truck and trailer combination. The most common configuration of a commercial truck is 18 wheels. 

It includes tractor units with two steer axles and four wheels and trailers with two to three axles and four to six wheels. Some may have 16 wheels, like heavy-duty dump trucks or specialized off-road vehicles.

What Do You Call A Truck With 10 Wheels?

A truck with 10 wheels is typically referred to as a “dually” or a “10-wheeler.” The technical term for a truck with 10 wheels is a “class 6 truck” or a “medium-duty truck.” 

These trucks are commonly used for local or regional transportation of goods and materials, as they are smaller and more maneuverable than larger 18-wheelers.

What Is A 4-Wheel Truck Called?

A 4-wheel truck is typically referred to as a “pickup truck” or a “light-duty truck.” These types of vehicles have a total of four wheels, with two on each axle. They are designed for light to moderate duty use and are commonly used for personal transportation, hauling lighter loads, and general utility work.

The Bottom Line

With 18 wheels, this type of heavy vehicle can carry heavy loads and navigate a wide variety of terrains. Understanding the number of wheels on an 18-wheeler and how they work together is just one aspect of appreciating the complexity and importance of the transportation industry.

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Robert Herrera

President & Automotive Expert at COR Wheels

Robert Herrera has been with COR Wheels for 17 years and has a great passion for the automotive industry. During his time at COR Wheels, he has driven and test-driven a variety of vehicles.

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