If you’ve talked to a driving lover in the past, they probably sing praises about manual transmissions. What’s the difference between a manual and automatic transmission? Let me clear things up for you.
Automatic transmissions replace the human element of shifting gears with some computers. Subsequently, the driving experience is muted, the cost is higher, and some of the control is lost. In a manual car, the driver has to select gears and controls the link between the engine and the wheels.
In this guide, I’ll explain the differences between an automatic and manual transmission, suggest which one is right for you, and highlight how they directly compare. Spoiler alert: it has nothing to do with little robots under your car’s hood.
How Does a Transmission Work?
Both forms of transmissions aim to achieve the same goal: they want to convert power from your engine and send it to your wheels.
How they do it is a little different.
When you look at the power in an engine, it’s too expensive and difficult to tune how much energy can be generated. The result is to use a number of gears.
Smaller gears are good at delivering quick acceleration but can’t offer high-top speeds. Large gears have much higher top speeds but take longer to accelerate the car.
Using this simple idea, a transmission will arrange a number of gears that get bigger sequentially. They’re held in a place called the gearbox.
As your car accelerates to a higher speed, it needs a larger and stronger gear to help step it to an even higher speed.
HowStuffWorks has a great image to help describe the process. The yellow knob on the top left is the manual shift knob in your car. It’s assigned to a number of different gears with purple idler gears spanning the gap.
If one of the idler gears is pushed against the blue gear labeled 2, for example, the car will be in second gear. If you look at the red gears at the bottom, you’ll notice that they get bigger from 1 to 5. This goes back to the point I was mentioning earlier about gear size.
Once the purple gear is pushed against a blue one, it engages the blue gear which spins the red gear. This controls how the engine is transferred from the engine (green shaft and gear) to the differential.
How Manual Transmissions Work
With a manual transmission, it’s all down to the driver’s actions. It’s almost as if the car is laying all the gears in front of you and asking you to pick which one you want at any given time.
Knowing how to drive a manual car is easier than you might think. It’s the same as an automatic car, with the addition of a clutch pedal and gear shifter.
Personally, I think manual transmissions are easy to theoretically understand than automatics since you are physically moving parts and seeing an immediate response.
The clutch is used to engage and disengage the engine from the transmission. When it’s engaged, the green shaft is driving the green gear which is tied to the rest of the assembly. When it’s disengaged, it’s not. The engine will just spin without power being delivered, like a hamster running in its wheel.
The driver will push in the clutch, select the appropriate gear with their right hand by maneuvering the shift knob, then release the clutch. Now the car is in gear and the engine is transferring its power to the wheels.
As the car revs higher and goes faster, the driver needs to do this process again, but select a higher gear. The driver is performing a constant dance of listening to the engine, checking the tachometer, and adjusting what gear they’re in.
How an Automatic Transmission Works
Rather than a line of gears, automatic transmissions use planetary gears. They’re assembled around a central gear and mesh in different combinations. In between are small friction clutches which engage the different clusters of gears.
As a result, you have a number of gear ratios that can be achieved without the space required to provide physical gear of those sizes.
There are sensors to determine which gear should be used, and fluid inside of the transmission makes the magic happen.
As a driver, all you have to care about is throwing it in Drive and hitting the gas or brake whenever you want.
Types of Automatic Transmission
There are a few different types of automatic transmission. Standard automatic transmission is the one that I described earlier.
Continuously Variable Transmission (CVT)
CVTs have been around for a while, but they just don’t seem to have a soul. I’m not being dramatic, that’s just the general consensus.
You know when you’re driving a car and you can hear the engine winding up, revving higher, then shifting and restarting the process? CVTs don’t do that.
It uses pulleys instead of gears. It can hold a constant rpm as you accelerate, and it just doesn’t feel right. In reality, it’s more mechanically efficient since the pulleys can make a ton of different gear ratios.
Cars have been pushing CVTs for a while, but they don’t get the attention that a standard automatic transmission gets. They typically wear more often and cost more money to repair.
To achieve smoother shifts, a dual-clutch gearbox uses two clutches that alternate when a gear is changed. Not only does this make the ride smoother, but it also speeds up the shifting process.
For instance, the first clutch could activate gears 1, 3, 5, and 7 while the second clutch activates gears 2, 4, 6, and 8.
Automated Manual Transmission
What happens when a mommy automatic transmission and a daddy manual transmission really love each other? You get an AMT.
This is a hybrid between the two systems. It’s mechanically set up just like a manual, but the clutch and shifter are controlled hydraulically without your input. It’s a less expensive option than an automatic one.
You can also manually shift this transmission if you move the shift knob up or down.
Manual vs Automatic Transmission
Let me take a second to explain the differences between a manual and an automatic. You already know what the mechanical differences are, but here are the different traits as a result of those differences.
Ease of Driving
With a manual, there’s an added element of difficulty when it comes to driving. Right now, I can feel every stick-shift driver rolling their eyes, but you have to admit that it’s true (come on guys, I’m one of you).
The simple fact is that there is an added pedal, a need to listen to the engine and watch the tachometer, and a knob that you have to move around during your trip.
You definitely get used to it after a while, but it’s still harder than driving an automatic where you can just stomp on the gas and brake as you’d like.
How Annoying Traffic Is
People driving manual transmissions want to pull their hair out when they’re stuck in traffic. The constant low-gear shifts and then back to neutral is definitely infuriating.
Plus, cars with high or low horsepower tend to have a hard time in first gear with plenty of lurching.
Meanwhile, in an automatic, you just match the car’s speed in front of you and turn up the radio to ease your mind.
The Driving Experience
This is a topic that I have a hard time describing to people who don’t drive a manual: the driving experience.
When you’re behind the wheel of a manual car, it just feels completely different. You feel like you and the car are in symbiosis as you drive. The car won’t make decisions without your input, and it will give you visual and audial clues as to what to do.
Maybe it’s a little lofty of me to think this, but I firmly believe that you get a better driving experience with a manual transmission.
What Do the Pros Use?
When you’re comparing two options, you might wonder what the professionals choose. In almost every case, the pros are using manual transmissions.
Look at NASCAR, WRC, or Formula 1 and you’ll be hard-pressed to find an automatic transmission. For Nascar typically an Andrews A431 manual transmission is used.
WRC cars will typically use either a sequential or H-pattern gearbox. F1 race cars generally use a hybrid sequential gearbox which basically semi-automatic with paddle shifters.
Why? It’s due to the benefits of a manual transmission. More control, a better feel, and a more refined driving experience. Plus, NASCAR drivers usually don’t have to deal with low-speed traffic unless they made a wrong turn.
The Overall Control
On roads that are slippery, control is everything. One way to fix that is with some snow tires. Another way is to pick a car that offers more control over your engine.
In a manual transmission, you control what gear you’re in at all times. Want to stay in low gear to get better a response? Not a problem.
Need to down-shift so you can rev hard and pass the girl next to you on the highway to impress her? Fire away.
Manual cars give you a level of control that you won’t get in an automatic. Even in “manual mode” in an automatic car, the onboard computer is making most of the big decisions for you and overrides you.
Which Option Sells More?
If these transmissions were part of a popularity contest in America, the automatic would win by a mile. According to CarMax, manual transmission sales were less than 5% of the total car sales in 2020. The exact number was 2.5%.
That’s embarrassingly low for people who love manuals.
Variety of Cars
Since the sales are so low for manuals, you might already predict the outcome of this section as well. The variety of cars for manuals is much more sparse than automatics.
There are only a handful of cars that offer strictly manual versions of their car. At the same time, a vast majority of cars in the American market don’t offer a manual option at all.
Reducing Distracted Driving
Distracted driving is a huge issue across the globe. It’s so tempting to eat your food while checking your phone and jamming to the radio. Until driverless cars come along, this habit will continue to hurt and kill people.
One way to reduce distracted driving is with Tesla’s autopilot. Another way is to grab a manual transmission.
Since you have to give the car your full attention to hit your shifts, you can’t get preoccupied with other activities. Plus, you have to keep both hands and feet free to operate the car if it’s manual.
Another difference between these two transmission styles is the cost. Since manual transmissions are mechanically simpler, then the cost is usually lower. This applies to the upfront cost to buy it as well as the cost to maintain the transmission.
If you look at a Kia Forte and compare the exact same trim level as an automatic or a manual, you’ll see a difference of up to $900 in favor of the manual.
What Happened to 10 and 2?
Since you have to use both hands with a manual, the driving style is different. You won’t have your hands on 10 and 2 most of the time. You’ll be steering with one hand and shifting with the other.
Put Your Feet to Work
The same is true for your footwork. Instead of resting your left foot while driving, you’ll have to keep it near the clutch pedal at all times.
Don’t rest your foot on the pedal though. This will engage the clutch and keep it in the “open” position ready to grab the next gear. More wear-n-tear means components failing earlier than they should and the goal is to make your car last longer.
Which Option is Right for You?
With all of that information covered, there’s a single question left: which option is right for you? Should you grab yourself a manual or automatic transmission in your car?
If you want my honest opinion, either option is fine.
If you want a purer driving experience, more control, and a requirement to pay attention to the road the whole time, you should get a manual.
For a driver who wants a casual cruise around town, finds themselves in traffic regularly, and wants something simple, you need an automatic. This is probably why automatics outsell manuals by orders of magnitude in America.
Now you know the difference between an automatic and manual transmission. I even covered which option is right for you and some of the benefits of one over the other. If you want more comparisons or informational guides, explore the rest of my blog. Also, make sure you grab the perfect car care products and more that I highly recommend.