Transporting heavy cargo, especially on long distances, can be pretty challenging, and if you’re planning to start a transport business that is efficient and convenient to handle or carry goods, then you might want to check out bobtail tractors. 

Right now, you might be wondering what a bobtail tractor is. Don’t worry. We’ve got you covered with this comprehensive guide about the different types of bobtail tractors.

We’ll also cover each type’s benefits and drawbacks to ensure you’re investing your money in the right transporter.

What Is a Bobtail Tractor?

A bobtail tractor, also called a bobtail truck, is simply a semi-truck without a trailer attached to it. The key components of a bobtail tractor include the internal valves, excess flow valve, tank percentage gauge, Pressure relief valves, meter, float gauges, ball valves, backchecks, hose, and valve filling connector. 

The origin of the term bobtail about the truck was derived from two popular beliefs. The first one was said to have originated from the bobtail cats, a breed of cats with short and stubby tails since a semi-truck without a trailer looks somewhat truncated or cut short. 

The second belief was from Jingle Bells, a popular holiday song. The lyrics in the song say bells on bobtails ring, which was said to refer to the horsetail cut style or the way the horse’s tail was cut short to prevent them from entangling with the sleigh.

Also, there’s a term associated with bobtail trucks—and that is bobtailing, which means when a semi-truck is driving without an attached trailer.

In general, a bobtail tractor measures 24 feet long, 13 inches in height, and 96 inches in width. Its weight, which is distributed to the front, center, and back of the truck, ranges about 20,000 pounds, including the diesel exhaust fluid (DEF) tank, full fuel, and two drivers. 10,000 pounds of the weight is on the steer axle, while 9,000 pounds are on the drive axles. 

But the standard total weight may vary, depending on the unique specifications and size of the bobtail tractors.

Type of Bobtail Tractors

The three common bobtail tractor types are Semi-Truck or Running Bobtail Truck, Small Bobtail Truck, and Straight Propane Truck.

A semi-truck or running bobtail truck is simply a small-size semi-truck without an attached trailer. This type of bobtail tractor consists of two components: a tractor unit and a trailer. 

Small bobtail trucks are small to medium-sized trucks without an attached trailer with all their axles attached to the same chassis. Due to their size, this type of bobtail tractor is limited to light or medium-weighted cargos or applications, such as transportation of bakery products, eggs, or dump carrying. 

A straight propane truck is a modified bobtail tractor with a tank specially designed to carry propane on the rear side of the truck and air horns. The tank is round in shape, has a storage capacity of about 1000 to 500 gallons, and can maintain adequate temperature and pressure while transporting propane. 

This type of bobtail tractor is typically used for supplying or delivering propane to farms, auto dealers, and fuel stations.

Bobtail Tractor Pros and Cons


A bobtail tractor is widely used to carry or transport goods, including raw materials, consumer, and finished products. Goods that are commonly transported are food like eggs, meat, cheese, bakery products, milk, and ice cream, among others. Consumer and other finished products include toys, books, clothes, furniture, electronics, and more.

Some bobtail tractors are specially designed to carry or transport petroleum or gas products like propane. In addition, they can also be used to haul heavy cargo over long distances at higher speeds as long as the total cargo weight doesn’t exceed the appropriate load weight. 

Moreover, bobtail tractors can also be used to tow large or bulky items, such as machinery, car, or boats


One of the major drawbacks of using a bobtail tractor is it’s harder to maneuver or more dangerous to drive, especially on winding, wet, slippery, or snowy roads.

The standard brake system of a truck functions best with a full load as the weight of the trailer will act as a support to hold the truck tires down. Since a bobtail doesn’t have an attached trailer, the brake system will navigate differently as the overall weight of the truck will not be distributed equally.

So when the truck driver slams on the brakes or maneuvers suddenly, the chances of the truck tipping forward, skidding off the road, or losing control is high because the weight is spread over the two front wheels, and less weight on the rear wheels, which results in not generating friction. It can cause accidents, which is dangerous to both the drivers and the civilians on the road.

A bobtail tractor also generates increased speed compared to fully-loaded trucks, which poses the risk of an accident. Due to a lack of freight, the spring suspension’s compressibility will not work properly, which supports the weight of the vehicle and absorbs the road shocks. 

Moreover, driving a bobtail tractor is more exhausting to truck drivers because they need to be more attentive and more likely to change the driving style to suit the road conditions.

Safety Driving Tips

Bobtail tractors can be difficult to maneuver and drive, so it’s good to know the safety precautions truck drivers can practice preventing accidents.

When driving a bobtail tractor, vigilance and caution should be observed by monitoring nearby vehicles, keeping an eye for other bobtailing truckers, and reducing the driving speed, especially when the road is wet or slippery. It’s also a good practice to check weather conditions before driving. 

While driving, make sure to ease on the brakes and allow a longer following distance between you and other vehicles to ensure a safer stop and reduce the chances of slamming on the brakes.

Another safety precaution to practice is to check the truck’s clearance, which is the distance between the axle and the base of the truck’s tire. A higher truck clearance can result in an increased risk of collision with a tunnel, signpost, or other objects on the road. It’s also good to avail bobtail insurance to protect since it covers accident costs.

Final Thoughts

Bobtail tractors are simply semi-trucks without attached trailers, which are efficient and cost-effective vehicles to transport goods and products. They provide ease of hauling heavy cargo even on longer distances.

Driving a bobtail tractor may have its challenges as there are certain restrictions and parameters to keep in mind, but you can reduce the risk of accidents by considering all relevant information above to help you.

Editorial Contributors
avatar for Alora Bopray

Alora Bopray

Staff Writer

Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today's Homeowner. She earned her bachelor's degree in psychology from the University of St. Scholastica and her master's degree from the University of Denver. Before becoming a writer for Today's Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she's not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.

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