These days there are as many types of car transmissions as there are types of cars. So what is a transmission, exactly?
A transmission is a vehicle's gearbox and it allows the engine’s power to be converted into momentum. To put it simply, the transmission applies the engine power to larger and smaller gears as needed to change the momentum at a given speed. Obviously, it helps the car speed up, but it can also be used to slow it down. The type of transmission your vehicle has defines how the engine communicates its power to the different gears.
If you're not that well-versed in engine mechanics, the different transmission types might not mean much right now. But wait! Below we’ll briefly cover the most popular types of transmissions available today and give examples of each.
A manual transmission is the oldest transmission type for modern vehicles and is also the easiest to understand from a mechanical perspective. For some, this is the transmission they learned to drive on. For others, manuals seem difficult and scary. But what exactly is a manual transmission?
To understand that, let's first go over the basic parts that most transmissions have.
As we've said before, a transmission is the gearbox of the car. This gearbox contains several gear sets. A gear set is selected depending on the speed you need. The clutch engages with the correct gear set.
For a manual transmission to work, the driver must choose which gear set is needed with the gear stick. This is why you may hear manual transmissions referred to as a “stick shift”.
To shift gears in a manual transmission:
Before the 1980s, manual transmissions were the standard offerings for most cars. That’s because vehicle computers were not sophisticated enough to automatically control a vehicle’s transmission. As technology improved and vehicle computer systems became more advanced, automatic transmissions became the norm.
Still, many manufacturers offer manual transmissions for drivers who prefer them. Many drivers attest to the manual transmission as being a more exciting, involved, and even personal way to conduct their vehicles.
If you're looking to go manual, here are a few choices to consider.
To drive a manual behind the wheel of a sports car, try the Toyota 86. The 86 is light, sleek, fast, corners well, and is reasonably priced.
To get the ultimate in hands-on, off-road driving, get a manual Toyota Tacoma TRD Pro and see how adept you are at managing the gears as you drive off-road.
Another great example of a manual is the Corolla Hatchback.
If you started driving in the mid 80s or later, you most likely learned to drive with an automatic transmission. Automatic transmissions are like manuals in that they have gear sets and a clutch, but the actual selection of the gear and “dropping” of the clutch is controlled by an on-board computer. Some might be thinking: “But, there’s still a gear shift. So what's different?”
Whether you’ve got a gear shift in the center console or behind the steering wheel, you’ll notice that the shifter for an automatic transmission is more simplified than the manual gear stick. On an automatic shifter, you’ll find P for park, R for reverse, N for neutral, and D for drive. Some may allow you to select from the lowest gears, 1 or 2, for example, to help with ascending and descending steep roads.
"What about the S-D? Or the plus and minus?" Good question! Some automatics have a manual mode so you can take control of the gears if you want to. Some allow you to shift up or down based on the + or - in a limited capacity. By limited capacity, we mean that most vehicles won’t allow you to downshift into a very low gear at high speeds -- this could damage your engine and the computer won’t allow the driver to do so.
Prior to the 1980s, automatic transmissions weren't as capable as manuals. But as car manufacturers got better at making them, they became the standard. Now, more than 90% of drivers in America have an automatic-transmission-driven vehicle.
Great examples of an automatic transmission are the Supra, 86 GT, and the Avalon.
The automatic transmission has seen high use in the last ~50 years, but it’s being edged out by a more advanced style of automatic, the Continuous Variable Transmission.
This is a newer type of transmission, works much like a traditional automatic, and is fast becoming the standard offering for most vehicles. Many vehicle manufacturers are opting for CVTs because they deliver better fuel economy than other transmissions and have a simpler, more reliable design.
So how do CVTs deliver on these advantages? They set the individual gears aside.
As we've said before, manual and automatics have gear sets. Continuously Variable Transmissions (or CVTs) instead have a driven pulley, a driver pulley, and a belt or chain. The belt or chain is wrapped between the halved pulleys. The pulleys press together and separate.
When a manual or automatic needs more or less speed, the clutch disengages from the current gear set and is made to select a new one. CVTs, on the other hand, never need to disengage. Instead, the belt is always running. What changes is how far apart the halves of the drive and driven pulley are. See the diagram above.
If the driven pulley halves are pressed together and the driver pulley halves are apart, that's a low gear. If the driven pulley halves are apart but the driver pulley halves are pressed together, that's a high gear. The CVT switches "gears" by pressing together or pulling apart the pulley halves.
Because the belt is always moving, it takes almost no time to find the right "gears." The pulleys do their magic, and your vehicle speeds on.
A continuous innovator in mobility, Toyota does the CVT a bit differently.
Some drivers say CVT's feel spongy, odd, or flat. A lot of drivers miss the pause between the clutch disengaging from the engine power and then re-engaging in a big burst of energy. They don't like that a CVT “switches gears” without switching gears.
However, those drivers shouldn’t have the same complaint with the Dynamic-Shift Continuously Variable Transmission CVT from Toyota. It gives you the feel of a traditional automatic with all the benefits of a CVT.
The Toyota Dynamic-Shift Continuously Variable Transmission has an actual first gear. This means that it has a real gear set for when you're driving 1-25 miles (40.23 km)-per-hour. Once you go beyond that speed, the CVT kicks in. This first gear is called a “launch gear”.
For vehicles like the Corolla XSE sedan and the Corolla Hatchback, there are other benefits to a Dynamic-Shift Continuously Variable Transmission. It has different modes to drive in, like sport mode, for when you need a little more pep. It also shares something in common with an automatic transmission—manual mode. This puts you in control of the CVT. The best part? It has paddle shifters.
Do you have more questions about transmissions? Check out our FAQ section. We answer great questions like: