Automatic Semi Truck – Explained

Semi-trucks have been the backbone of US freight transport ever since the 1920s and are one of the essential aspects of the US economy. Semi-trucks make up about 70% of all the US domestic freight transport, with the only alternatives being trains, planes, and boats, but we already know how underdeveloped or expensive those are. That means semi trucks have been around for over 100 years and are here to stay.

Now the automatic semi truck first came around in the 1970s in the US and has been growing exponentially popular since the recent decade or two back. Automatic transmissions improve fuel economy and make the driver’s life easier and driving safer, among other things. However, automatic semis are more expensive and complicated, which increases the chances of breakdowns and expensive downtime.

best semi truck automatic transmission

Semi Trucks Explained

The definition of a semi-truck, in broad terms, is that it’s a tractor with an engine that is capable of driving without any attachments. Furthermore, semi trucks have one or more independent/removable trailers that don’t have engines and rely on the truck’s engine to move. Semi-trucks are also called eighteen-wheelers, tractor-trailers, semis, and big rigs.

Apart from the driving cabin, almost all semi trucks in the US have sleeping cabins, unlike in Europe. In the US, there is also no length limit on the truck which is why they can get away with long hoods and huge sleeping cabins. 

Semi-trucks first came around in 1896 and were mainly used by car manufacturers for vehicle transportation. But by the 1920s, semi trucks started becoming increasingly popular, and today, they make up roughly 70% of all US freight transport. But when did automatic semi trucks come out? The answer is the 1970s, almost 80 years later.

Semi-truck driving was also considered one of the best blue-collar jobs up until 1980. Drivers had more benefits, higher pay, and the most time off than any other trade job. However, the Motor Carrier Act of 1980 largely deregulated truck driving, after which trucker unions had less and less authority. 

Today, how good or bad truck driving is, depends on the market. When times are good, truck driving is profitable, and drivers are happy for the most part. However, when times are bad, drivers have hardly any security, and all market drops will directly reflect on their wallets.

It’s also pretty difficult to start truck driving with licenses costing a small fortune, and the companies willing to pay for the necessary education also require at least a two-year exclusive contract. And during those two years, you guessed it, you will be working for basically minimum wage.

Still, that doesn’t change the fact that semi trucks are crucial, and the American Trucking Association estimates that the US will need about 110,000 new drivers every year in the next decade. 

What Percentage of Semi Trucks Are Automatic

Just a couple of decades ago, manual transmission semi trucks were still very much preferred by both drivers and fleet owners. However, as automatic transmission technology progresses, the trends are changing, and today, about 50% of all semi-trucks on the road in the US have automatic transmissions. At least, that’s according to 

And the only reason that percentage is so low is because of all the older trucks still on the road, but the percentage of automatic semis will grow exponentially in the future. As proof of that, one Emery Larick, a Quora user who works for a semi-truck truck dealership, says that 90% of all the new semis he delivers are automatics. 

Furthermore, the product strategist for Mack Trucks states that 94% of all new Mack trucks delivered have automatic transmissions, a statement you can find on Moreover, 90% of all Freightliner orders are automatic transmissions, as well as 90% of all Volvo semi truck orders.

With Kenworth, the percentage of new trucks with automatic transmissions was at 70% in 2018, but it’s more than likely higher now, five years later. But in the end, the answer to what percentage of semi trucks are automatic is 50%.

Automatic Semi Trucks Pros and Cons

Automatic transmissions have been on the rise in the passenger car industry for about two decades now, and for good reasons. But when it comes to automatic semi truck pros and cons, those same positive reasons are significantly amplified; however, so are the negative sides of automatic transmissions. So, here is what we mean.

Automatic Semi Trucks Pros

Although there are fewer automatic semi truck pros than cons, the pros that they do have are much more significant for both drivers and fleet owners.

Fuel Economy

One of the main reasons automatic transmission cars are so popular today is because of better fuel economy. And the same applies to semi-trucks; however, it’s much more important. A semi-truck burns much more fuel and directly eats away both the driver’s profits and the fleet owner’s. 

Furthermore, the average semi truck does about 50,000 miles a year, and with a fuel economy of roughly 6 mpg, even a 5% increase in fuel efficiency goes a long way. 

Easier To Operate

We all know that automatic cars are easier to drive than manual ones. As a matter of fact, most drivers in the US never learn to drive a manual. Well, if we consider that most manual semi trucks have between 14 and 16 gears, we can only imagine how much easier it is to drive one with an automatic transmission. 

Furthermore, automatic transmissions significantly lower the time it takes to teach a new driver,  which is extremely important in a profession that’s missing a huge number of workers. Moreover, imagine shifting through so many gears manually in stop-and-go traffic. That means shifting through at least four gears just to get up to 10 mph.

And let’s not forget, that means pushing the clutch in at least four times,  which brings us to another issue, health. A lot of older semi-drivers have serious problems and operations done on the left knee, all because of the hard clutch pedal. So, with an automatic transmission, you will be looking after your health as well. 

Automatic Semi Trucks Cons

All the cons of an automatic semi truck have to do with the complexity of the automatic transmission compared to a manual one. Meaning if money isn’t too big of an object, automatics remain the far superior choice. 

More Expensive To Buy

A brand new automatic semi truck price is roughly $5,000 to $10,000 higher than their manual alternatives. That, truth be told, isn’t a huge difference when we consider that a brand-new semi-truck price can be close to a quarter of a million dollars. However, to someone buying a fleet of ten or more semis, the price difference can quickly add up. 

More Expensive To Maintain

Automatic transmissions are much more complex than manual ones that only have a couple of sets of gears and a few cables. That means if anything goes wrong with an automatic transmission, the repairs will be at least two times more expensive on average. Not to mention that an automatic transmission takes longer to repair, equaling a longer downtime which translates into profit losses.

Less Reliable

Given that automatic transmissions have a lot more moving and electronic components, it means a lot more can go wrong, and it does. Moreover, automatic transmissions in semi trucks start developing performance issues at around 250,000 miles,  which is something that rarely ever happens with manual transmissions. And let’s keep in mind that semi trucks last over 750,000 miles on average.

what percentage of semi trucks are automatic

Which One Is Better – Manual or Automatic Trucks

By now, it’s evident that automatic semi trucks are far better than manual ones. Automatic trucks consume less fuel, are easier on the driver, make it easier to learn how to drive, and are not much more expensive than manual alternatives. Moreover, roughly 90% of new semi trucks are sold with an automatic transmission.

That said, there are still some circumstances where an automatic semi-truck cannot replace a manual one. And that’s for drivers who are not operating a standard 53′ trailer and, instead, deal with oversized and overweight loads. Under those conditions, a manual truck gives you much more control over the drivetrain, which is crucial with loads of over 80,000 lbs or more.

So, for 53′ dry vans and even smaller flatbeds, an automatic transmission is a far superior choice if you are looking at semis that are no more than a decade old. Otherwise, a manual is the better option. However, an automatic semi also copes well with oversized loads, so if you don’t want to learn how to drive a manual, you might get away with an automatic.

Are Semi-Trucks Automatic

Semi-trucks can be both automatic and manual, depending on what the buyer needs or wants. Furthermore, automatic and manual transmissions can be found in all types of semi-trucks, box trucks, dump trucks, fire engines, etc.

The point is there are no exclusively manual or automatic trucks, regardless of the type, class, or intended use. And as we already mentioned, about 50% of semi trucks on the road right now are automatic, and the other 50% are manual. But that ratio is quickly shifting in favor of automatic semis since about 90% of new trucks sold have an automatic transmission.


Q: Are most semi trucks automatic?

No, not most semi trucks on the road right now are automatics. The percentage of automatic semi trucks is about 50%, with the other half being manual. However, about 90% of new semi trucks in the last couple of years are sold with an automatic transmission.

Q: Do semi trucks have a clutch?

Yes, some semi trucks do have a clutch. All semi-trucks that have a manual transmission also have a clutch pedal. That said, none of the semi trucks with an automatic transmission have a clutch.

Q: Are automatic semi trucks good?

Yes, automatic semi trucks are very good, and the statement is justified by the sales numbers from Freightliner, Mack, Volvo, and Peterbilt. Roughly 90% of all trucks the aforementioned brands sell are specced with an automatic transmission.

Q: Are automatic semi-trucks more expensive?

Yes, automatic semi trucks are more expensive than manual transmission alternatives. An automatic semi can cost roughly $5,000 to $10,000 more than the same truck with a manual transmission.

Q: Is it hard driving a manual semi truck?

Yes, driving a manual semi-truck, especially as a beginner driver, can be extremely difficult. Manual semi trucks can have up to 18 gears and sometimes even two gear shifters. On top of everything, when the truck is under load, the driver needs to shift about nine to ten times just to get up to 50 mph.

Q: What is the most common transmission in semi trucks?

At this time, the automatic transmission is by far the most common in new semi trucks since automatic semis make up about 90% of all new trucks sold in the last couple of years. However, if we look at all the trucks on the road right now, manual transmissions make up about 50% of all the registered semis.

Final Words

Ultimately, automatic semi trucks obviously have a lot more significant pros than cons; otherwise, they wouldn’t be so popular. About 90% of all semis sold in the last couple of years have an automatic transmission, even though they cost $7,500 more on average. And that’s not too surprising considering how much easier automatic semis are to drive and how much safer they are because of that, plus considering how much money the owner will save on fuel. That said, automatic transmissions are more expensive to maintain and last significantly less than manual transmissions.

Ibro Cehic

Ever since I was bitten by the automotive bug during early childhood I was obsessed with cars. My first driving experience came when I was ten and I already started tinkering with cars and motorcycles at thirteen. So, right from the beginning, I knew my life would revolve around cars, even if I wasn’t sure how that would happen. And today, thanks to my second passion, writing, I get to share my love for automobiles with other enthusiasts through my articles.

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