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How Many Gears Does A Semi Truck Have? Surprising Facts

Are you in the market for a semi truck but not sure how many gears does a semi truck have? Are you looking into buying one and want to know all the details before investing your hard earned money? Then, this blog post is perfect for you! You’ll learn everything there is to know about these powerful heavy-duty trucks and some surprising facts that may surprise even experienced drivers.

With so many models on the market today, we’ll also cover simple yet significant questions like how many gears does a semi truck have. So join us as we explore what makes these amazing vehicles tick, ensuring that you get just the right fit for your business needs.

The History of Semi Trucks

The first-ever semi-truck was created by Alexander Winton, the founder of the Winton Motor Carriage Company, as a practical solution to deliver his automobiles to customers. Since then, several manufacturers have made significant strides in technological advancements, and design developments have increased the productivity of semi-trucks to what it is today.

6 Surprising Facts about Semi-Trucks

1. Diesel fuel is preferred over gasoline

Diesel fuel contains more usable energy compared to gasoline, meaning that a higher percentage of it is used to move the vehicle down the road. In fact, diesel can provide up to 30% more distance per gallon compared to gasoline.

For larger vehicles like semis that require more power to accelerate and frequently travel long distances, this greater fuel efficiency is a crucial factor in keeping fuel expenses in check.

2. Standard semi-trucks have 10 gears, but big rigs may have 18 gears

Standard semi-trucks typically have 10 gears, some larger models can have as many as 18. These additional gears are crucial for navigating different terrains and inclines, especially when hauling heavy cargo.

So, if you’re searching for a semi-truck that can handle it all, consider one with 13, 15, or even 18 gears. You won’t regret the extra control and precision they provide.

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How-Many-Gears-Does-A-Semi-Truck-Have (3)

3. Big rig engines are designed to run nonstop

As a prospective buyer of a big rig, you may wonder how often you’ll need to shut down your engine. The good news is that big rig engines are designed to run nonstop. These engines were made to handle extended duty cycles and can easily power through long stretches of driving.

However, it’s important to keep in mind that excessive idling can lead to fuel waste and internal engine issues. Each hour of idling can consume a whole gallon of diesel fuel, which adds up quickly both in terms of cost and environmental impact.

4. It can be dangerous to make a U-turn in a semi-truck

Making a U-turn in a semi-truck can be a dangerous move that can put yourself and other motorists at risk. Tractor-trailers are huge vehicles, averaging 70-75 feet in length and requiring at least 55 feet of space to make a safe U-turn. Unfortunately, U.S. highways are only 12 feet wide, which means that making a U-turn in a semi-truck is not only unsafe but also illegal. Moreover, a semi-truck has several blind spots that can cause accidents if you’re not careful.

So, unless you have controlled conditions, like being in a parking lot or designated area, you should avoid making U-turns with your commercial truck at all costs to ensure the safety of everyone around you.

5. Freightliner has a 40% share of the commercial truck market

As the best-selling semi-truck in America today, Freightliner dominates the commercial truck market with an impressive 40% share. With over 190,000 trucks sold each year, it’s clear that Freightliner’s reputation for quality and durability is well-deserved.

But it’s not just about sales numbers – Freightliner’s commitment to innovation is evident in their new line of all-electric commercial vehicles, the Freightliner e-Mobility. With two models set to hit the market soon, including the eCascadia and eM2 106, Freightliner is poised to continue leading the way in the world of commercial trucks.

6. Aerodynamic mud flaps boost fuel efficiency and safety

Mud flaps might not seem like an important component of a semi-truck, but they are actually quite useful. Not only do mud flaps protect other motorists from debris kicked up by the tires, but they also help to conserve fuel by reducing wind drag around the cab, trailer, and wheels.

According to studies by NACFE, installing proper aerodynamic mud flaps can lead to a 1-5% improvement in fuel efficiency – a small investment that can pay off big time in the long run.

Why Do Semi-Trucks Have so Many Gears?

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How-Many-Gears-Does-A-Semi-Truck-Have (1)

When it comes to purchasing a semi-truck, it’s important to consider the weight it can handle. Most semis can pull loads up to a staggering 80,000 pounds, which is the equivalent of 25 Subaru Impreza sedans. It’s no wonder that these trucks require a lot of force to get moving and keep under control.

That’s why the transmission is crucial in ensuring the truck functions at its best while keeping the driver safe. The large number of gears and split-gears available prevent each gear from requiring higher RPMs, which can lead to less fuel efficiency and more wear.

Related: How Many Tons Can a Dump Truck Haul


After learning about the various types of transmissions and the number of gears in a semi-truck’s transmission, it is clear that the answer to the question “how many gears does a semi truck have?” is dependent on the type of transmission used. Manual transmissions may range from 5 to 12 gears, while an automatic transmission could have as few as 10 or as many as 18 gears.

Transportation companies should understand their own vehicles’ capabilities and plan routes accordingly for maximum efficiency. Regardless of the complexity involved with understanding a semi-truck’s different types of transmissions and number of gears, this comprehensive guide can help anyone become informed before making their purchase decisions!

Timothy Ballard

I’m Timothy Ballard, owner of a used car dealership in Springfield. I love just about everything automotive, but I have a special place in my heart for trucks. I’m an ASE Certified Master Technician, so I know my way around a car. In my spare time, I enjoy traveling with my family and hiking new trails.

1 thought on “How Many Gears Does A Semi Truck Have? Surprising Facts”

  1. Semi-trucks come equipped with a varying number of gears, typically ranging from nine to eighteen. Commonly, these trucks are outfitted with two reverse gears and ten forward gears. To gain a comprehensive understanding of this topic, we recommend consulting the specialists at International Used Truck Centers. They provide valuable insights and expertise on this matter.


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