Automatic Transmissions and Class 8 Trucks: Are We Better with Them or Without?

Most truckers have strong opinions about automatic transmissions versus manual transmissions in their trucks. Some drivers find that driving an automatic makes their job easier, while others just can’t get used to driving a big rig without shifting gears. Some of the pros and cons come down to personal preference, while others are a matter of safety.


Semi trucks with automatic transmissions generally have more electrical problems than those with manual transmissions. They are also known to wear out trucks at a much faster rate than good drivers who drive manual transmissions. Another issue is that fewer semi truck mechanics are familiar with automatic transmissions than manuals, so it may take longer to have the transmission repaired.


One of the issues that drivers have noted when driving trucks with automatic transmissions is that they don’t handle well in winter weather conditions, particularly ice. The trucks can be changed to manual mode for winter driving, but the driver must know how to shift the truck properly to drive the truck in manual mode.

Some automatic transmissions have had issues shifting when they are not supposed to, causing the driver

Fuel Economy

Trucks that are equipped with automatic transmissions usually provide better fuel economy overall than standard big rigs. This is not the case when routes take drivers over mountains and up steep hills. Drivers who are experienced at shifting can get about the same fuel economy as an automatic transmission, but most drivers don’t shift at the best time and better fuel economy can be achieved by automating the transmission.

Driver Performance

Truckers seem to be divided on the issue of fatigue and paying attention to the road. Automatic transmissions give drivers one less thing to think about while they are driving down the highways. This can be a good thing because the drivers can be more focused on their surroundings and the traffic around them. It can also be detrimental because drivers tend to get bored on long trips and shifting can help them stay focused on the task at hand.

Some drivers feel that automatic transmissions allow inadequate drivers to get their commercial drivers licenses and pass company driving tests when they are not good enough drivers to navigate the freeways safely. Other drivers feel that driving a truck with an automatic transmission allows them to focus more on the road because they don’t have to think about shifting.

Most drivers seem to be most comfortable with the trucks they are used to driving, which means that drivers with years of experience generally prefer manual transmissions. These drivers are less likely to get in accidents and have problems on the road, but this probably has more to do with their experience on the road than the type of truck they drive.

Overall Impressions

For drivers that have hauled loads driving tractors with both manual and automatic transmissions, many agree that most of the advantages of an automatic transmission come into play when driving in the city. Drivers have to shift more when they are in the city dealing with traffic and stoplights, so they get more benefits from an automatic transmission than drivers who are out on the open road. Driving through treacherous road conditions including steep hills and ice requires skill and concentration as a driver, regardless of the type of transmission in the truck.

11 Responses to “Automatic Transmissions and Class 8 Trucks: Are We Better with Them or Without?”

  1. Dan says:

    I guess I’ll find out in the next few months! Just purchased one to travel Vancouver BC to Calgary AB.

  2. TJ says:

    Sounds like a great trip!

  3. Mike Mounsey says:

    As I read your article on automatic transmissions, it aroused my curiosity as to where your facts were gathered from. I couldn’t determine from your information when you were refering to true automatics or the more popular automated shifing transmissions, but clearly your statement about wearout is incorrect regarding an automated shift transmission, as Eaton provides an additional 250,000 mile coverage at no charge to an automated vs. standard shift transmission. It would be hard to imagine that they would do that if there were “wearout issues”. This is also in stark contrast to their 13 and 18 speed manuals, as they only provide a 300,000 mile warranty on those.

    Would that indicate something that they know about their own product?

    I would like you to answer one specific question for me, though.

    You state that the act of shifting focuses the drivers attention and fights fatigue on long trips.
    Exactly how much shifting is being done on the long, boring stretches of interstate where I see the
    greatest numbers of fatigue-related accidents?

    Perhaps, and this may not be an option for you, but perhaps you could actually drive an automated transmission truck before your next article on one.

    Mike Mounsey

  4. Len Madin says:

    I am having this discussion (argument) with my 29 year old son at the moment, he claims that the manual helps keep him awake. Rubbish, if that is what is needed to stay awake and fully alert then it is simple, MORE SLEEP is required. Only one this cures fatigue, SLEEP.

  5. TJ says:

    Good point!

  6. Randy says:

    Its all about cool factor. Automatics no doubt give better gas mileage because they shift at optimal shift points. And reliability… you cant beat how reliable a automatic transmission is. Eaton or even Volvo does not put a long warranty on a transmission to loose money.. Bottom line is there is nothing cooler than running through the gears of an 18 or 13 speed … or opening the door of a Custom Pete with a nice shinny extended shifter… or Kenworth or Freightliner.. whatever looking at a small short throw shifter either mounted on the dash or floor just doesn’t have the OL Skool cool factor. But lets face it new school can save you some money if that is your focus.

  7. Nathan Smith says:

    With regard to what Mr. Mounsey wrote about the longer warranties, that argument does not actually work in favor of the automatics. Longer warranties are an indicator of less confidence in the reliability of the product – case in point: the notoriously unreliable Korean automobiles and their 10-year warranties. A long warranty makes the customer more willing to buy something of lesser reliability.

  8. Frank says:

    Give me an auto any day. Save my left leg from falling off. The industry needs to face it, there are and will continue to be lots of noob drivers out there, they are much much safer to themselves and everyone else if they’re behind an auto. I don’t want a noob trucker driving a manual shift coming up behind me in the mountains when he just realized he’s in too high of a gear…

  9. preston says:

    as a driver that has driven both types I prefer a manual for the fact of the matter is I was on the side of the road with the transmission locked into 8th gear with only 80,000 miles on the truck I had no way of moving the truck so I had to be towed by the only tow truck co in the area and had to wait 5 hours for them to get there and that was on the back roads of Arkansas with out a shoulder

  10. CBento says:

    The biggest problem with automatic is the driver. driving automatic is another challenge, you need to learn again, the all new Allison is fantastic, but you have to know how to drive it, it’s very simple read the manual.

  11. Bubba says:

    I’ll stick to my auto for any job except a flat haul or filled tank. Those loads are much safer when you have better control on the gearing.

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