Manual and automatic transmissions are the two most common vehicle transmission types in the U.S. Both types connect a vehicle's engine to its wheels to make the vehicle move. Every transmission features a gearbox containing a system of gears, and these gears alternate to provide different levels of power to the wheels according to the vehicle's needs.
For example, a car driving uphill requires a different gear configuration than a car driving on a flat road. Manual and automatic car transmissions each have advantages and disadvantages, and the car transmission that's best for you depends on your style of driving.
Manual vs Automatic Pros and Cons: How Do Manual and Automatic Cars Differ?
The most obvious difference between automatic and manual vehicles is the layout of the shifter — that is, the lever that changes the transmission's gear placement, usually located between the two front seats of the car in newer models and sometimes attached to the dash or steering column in older models.
Automatic cars typically have simple shifters that let you alternate between four driving modes: park, reverse, neutral and drive, in that order. Many automatic shifters sometimes allow you to shift gears to handle specific driving conditions.
Manual transmission cars, also known as stick shifts, are different. They tend to feature shifters with five to seven forward speed gears, plus a reverse gear. The gears are numbered, with higher numbers corresponding to a greater distance traveled per engine revolution.
In addition to a more complicated shifter, manual transmission vehicles have a clutch pedal. The clutch pedal, which sits to the left of the acceleration and brake pedals, allows the driver to engage the vehicle's clutch plate to control the vehicle's speed. To drive, you hold down the clutch pedal while starting the engine then gradually ease off it while pushing the accelerator. You also hold down the clutch pedal (with your foot off the gas pedal) when shifting gears.
You can easily calculate how far a car can travel in one engine revolution by dividing the circumference of a tire by the product of the gear ratios of the differential and transmission. If the sixth-gear ratio is 0.5, then the car travels 53.3 inches per engine revolution in sixth gear, about six times further than in first gear.
The Benefits of Automatic Cars
Automatic cars are the most popular American cars by far, mainly owing to how much simpler they are to drive. Because automatics lack clutch pedals, many drivers see them as having easier learning curves and requiring less maintenance. Driving a stick shift takes much more practice than driving an automatic, so there's a greater risk of accidents while learning to drive one.
Driving through hilly areas in automatic cars is also easier, as you don't have to switch gears each time the steepness of the road changes. In particular, switching from a dead stop to a steep climb is less tricky in automatic cars, because there's almost no chance of the car stalling while you manage the gears and clutch pedal; there's also little to no risk of the vehicle rolling backward once you engage the gears to move forward. Stalling isn't a problem in automatic cars unless there's a mechanical failure. You don't need to worry about your car losing power if you're at a stop light and forget to activate the clutch.
Another benefit of automatic cars is that you can keep your hands on the steering wheel at all times. You can respond to road hazards more quickly since you're not fiddling with the shifter as often. Similarly, heavy traffic isn't as much of a problem for automatic drivers as it is for manual drivers since you don't have to change the gears in a constant stop-and-go fashion.
Due to their simplicity and convenience, automatics are ideal for urban settings, and they're the perfect cars for new drivers to learn. Also, due to the popularity of automatics, selling one is easier when it comes time to upgrade to a new car.
The Drawbacks of Automatic Cars
Although automatic cars are convenient and easy to drive, many drivers feel they don't perform as well as manuals, since they sometimes switch to the wrong speed gear when they interpret driving conditions incorrectly.
When automatic cars switch to higher gears at the wrong time, they waste engine power and cost the driver money in wasted gas. At times, switching to a lower gear in a manual car provides a needed burst of power, but automatic cars' transmissions are usually more cautious about making such gear switches on their own. As a result, automatic cars have a reputation for being less fuel-efficient than manual ones, though the fuel efficiency gap is no longer an issue for newer automatics, such as the 2019 Volkswagen Jetta.
Automatic cars require more maintenance because of their complex transmission systems. Many automakers charge more for automatic cars, which is another drawback.
The Benefits of Manual Cars
Automatics may be popular, but manual drivers are passionate about their vehicles. Access to speed gears gives manual drivers more control over their speed. They don't need to rely on their car to make basic driving decisions, such as whether to shift up a gear to ascend a hill. For experienced drivers, in particular, this intimate sense of control brings peace of mind, as it means the torque converter is less likely to waste energy.
Manual transmissions also require less maintenance and fewer repairs than automatic ones, owing to their simpler layouts. In the earlier days of the automobile, manual transmissions were the default. As a result, many drivers got so accustomed to them that they find automatics unnatural. For these drivers, manuals provide a satisfying tactile sense of engagement that automatics can't replace.
Manual cars are about $1,000 cheaper than automatics on average, as of 2019. In addition, older manuals have a greater fuel economy than automatics of a similar age. That's not just because manual cars lack fuel-draining torque converters. It's also because manual cars have lighter transmissions.
Another --somewhat odd -- benefit of manual cars is that they're less likely to be stolen. Fewer people know how to drive manuals than automatics, so car thieves aren't as capable of driving away with them.
Manuals also tend to have more gears than automatics, allowing them to tap the engine's full power in ways that automatics can't.
Finally, manual vehicles prepare drivers to handle just about any vehicle in the world, since switching from a manual to an automatic is much easier than vice versa.
The Drawbacks of Manual Cars
Like automatics, manuals have drawbacks. Most importantly, many drivers find them cumbersome. Manually shifting gears and managing the clutch pedal takes a high level of dexterity and situational awareness, especially for drivers who didn't learn to drive manuals from the get-go. Shifting gears in a manual requires taking a hand off the steering wheel periodically, making accidents more likely. Plus, shifters in manuals can tax your muscles and joints if you have to use them constantly, such as in stop-and-go traffic.
Another downside to manual transmissions is that they're less common than automatics. As of 2013, less than 4 percent of vehicles were manuals, and fewer and fewer companies are interested in selling them. The Porsche 911 and Toyota 86 are two of the few cars left with manual transmissions. Because so few people drive manuals, reselling a manual when you want to upgrade can be difficult.
What's more, although some manual cars come with an automatic driving option, sports cars often don't, so you're stuck with what you have. In addition, the clutch in manual cars may need repairs or replacement after long-term use. Missing gears while shifting wears out the clutch, and a clutch that fails while you're driving can put you in danger.
Manual vs Automatic: Final Considerations
Manual and automatic cars both come with benefits and drawbacks, but they're not your only options.
A third transmission type, the continuously variable transmission, is available as well. Though the driving experience is nearly the same as an automatic, technically a CVT has a single gear. It uses a belt-and-pulley system to transfer engine power to the vehicle's wheels, allowing for an infinite gradient of ratios.
Fuel-efficient and fairly quiet due to their lack of gear-shifting, CVT transmissions are common in hybrid vehicles, and they offer a smoother, more seamless driving experience than either manual or automatic transmissions. However, many drivers feel CVTs have slightly uncomfortable acceleration and handling, plus a faint drone that some find irritating.
Many modern vehicles throughout the industry -- especially Japanese and Korean brands -- use CVTs, including the Honda CR-V, Mitsubishi Outlander Sport and Nissan Rogue. Just as manual cars are more common in Australia than the U.S. for cultural and economic reasons, CVTs are more common in Japan for the same, though their popularity in the U.S. has been growing.
There's also something called a dual-clutch transmission or DCT. Popular in Europe, this transmission type also acts like an automatic but it uses two clutches, each with opposing gearing (one has first, third and fifth gear with the other has second, fourth and sixth gear). Originally pioneered in Formula One racing, these transmissions shift much quicker than conventional automatics and they're most common in performance-oriented models like sports cars, supercars and the like. They allow for nearly-instantaneous gear changes either automatically or through steering wheel-mounted paddles that the driver controls.
There are other a few other considerations to keep in mind when deciding which type of transmission to buy. Although manual cars typically come with five or six gears, the full gamut ranges from three to seven gears, with old cars such as the original Ford Mustang having three and upscale sports cars such as the Porsche 911 having seven. More gears mean more flexibility, but it also means more complexity.
Whether you should get a manual or automatic depends on your driving preferences. If you like convenience and ease of use, an automatic is probably for you. If you prefer strong a sense of control over your car, however, you might be better off with a manual.