In general, there are three different types of transmissions. Even if you don't know much about how a transmission works, you have probably heard of the manual and the automatic. The CVT is the newest type of transmission. It is sometimes referred to as the shiftless transmission and is a type of automatic.
What Does CVT Stand For?
Autotrader explains the term CVT stands for continuously variable transmission.
Advantages of CVT
Depending on the vehicle and the driver, a CVT can provide a smoother driving experience when comparing it to a traditional automatic.
According to Carfax, one of the most significant advantages to having a CVT is that they are often more fuel-efficient than a regular automatic. This is part of the reason that they are becoming a more popular choice for automakers in many vehicles.
How Does a CVT Work?
In order to see how a CVT works, How Stuff Works explains, you need to understand a manual and a traditional automatic. A manual has a set number of gears, and the driver determines what gear ratio they need. An automatic also has a set number of gears, but it uses a hydraulic system that responds to pressure created by the conditions to determine the gear needed without any input from the driver.
A CVT is similar to an automatic in that it doesn't use any input from the driver, but that is where the similarities end. A CVT doesn't have any gears. Instead, it has two pulleys. One pulley connects to the engine, and the other connects to the wheels. A flexible belt connects the two pulleys
The width of the pulleys changes depending on how much power the vehicle needs. When one pulley gets larger, the other one gets smaller. Since neither the pulleys or the belt are fixed, they can provide an infinite number of gear ratios, unlike the automatic, which has a set number of gears.
Not all CVTs are created the same. The most common type is the pulley-based, but some other types include the Toroidal CVT, which uses rotating discs along with power rollers to produce the same result as the pulleys. The hydrostatic CVT uses pumps to control fluid flow, which then produces a rotational motion.
What Is Launch Gear?
Toyota recently made some changes to its CVT. CNET says it now uses what they call a Launch gear to provide drivers with the feeling of a conventional transmission. The launch gear is almost like the first gear in a regular automatic transmission. As the vehicle speeds up, the transmission will switch this out, so it starts working as a CVT. Toyota says that using these new fixed gear ratios will not only feel more like a regular transmission; it will also increase belt efficiency and improve performance.
Which Is Better Between CVT and Automatic Transmission?
One of the advantages of a CVT is its ability to continuously change its gear ratio. This means that no matter what the engine speed it, it is always performing at its peak efficiency. CVTs often offer better fuel economy as a result, especially when driving in the city.
Digital Trends says that most cars equipped with CVTs offer a smoother ride than a similar car with a regular automatic. This is because the transmission never shifts. There is no abrupt downshifting when the car needs additional power, and there is no feeling of gear hunting that you sometimes feel with a traditional automatic.
A CVT is lighter than a traditional automatic, and this, combined with the smoother operation, helps to improve the fuel efficiency of vehicles that come equipped with a CVT.
Because of the lack of gearing, it is easier for CVT vehicles to find and maintain an ideal torque ratio as well. It has an easier time taking off from a stoplight and an easier time climbing difficult terrain because the variable transmission allows it to run in the right "gear" and stay there.
Disadvantages of CVT
While the lack of upshifting and downshifting is considered an advantage of the CVT, some drivers miss the sensation of the vehicle moving through the shift points. If you prefer a sportier driving experience, then the lack of fixed gears makes the ride less engaging.
Another complaint that drivers tend to make about a CVT is the loud droning sound that occurs during acceleration. This happens because the CVT forces the engine to continuously run a constantly high rpm as it gets up to speed. As Car Engineer explains, the general public has been less accepting of the CVT due to the difference in noise perception from mechanical or step automatic transmission.
CVTs can be expensive to repair or replace when compared to a conventional automatic transmission.
Some of the common problems that owners run into include overheating, slipping, and sudden loss of acceleration. Shuddering is also a common problem.
Since CVTs depend on the belts to operate, if these suffer from excessive stretching or too much wear, the transmission can completely fail.
AutoDNA explains common CVT Cons include:
- They have no feeling of connection between the accelerator and the engine during acceleration.
- There are limits on the engines that can work with a CVT in terms of power and size.
- They don't last as long as a conventional transmission.
- CVTs are harder to work on. Even basic maintenance often needs to be done by a trained mechanic.
Advantages of Automatic Transmission
According to Mister Transmission, while there are some advantages to having a CVT, traditional automatic transmissions also offer some benefits.
- They have a more connected feeling between the engine and the speed of the vehicle.
- The driver has a better sense of control with actual upshifting and downshifting.
- Automatic transmissions are less expensive to maintain.
- They offer a more engaging driving experience.
Disadvantages of Automatic Transmission
Like a CVT, an automatic transmission also has some downsides. Some of these include:
- They are less fuel-efficient than a CVT.
- Automatics produce more emissions.
- Drivers have to hunt for gears when climbing hills.
How Do Automatic Transmissions Work?
How Stuff Works explains that an automatic transmission uses gear sets, a hydraulic system, and a torque converter. The hydraulic system regulates the bands and clutches that control the gear sets, and a pump pushes the transmission fluid through. The fluid pressure forces the shift valves to open and close, which opens different gear circuits.
Now you know the difference between a CVT transmission and an automatic transmission. Which one works for you?
Sources:
https://www.digitaltrends.com/cars/manual-vs-automatic-transmission/
https://www.aamcoleessummit.com/Blog/Article/The-CVT-Transmission-Pros-and-Cons-You-Should-Know
https://www.sunautoservice.com/how-does-an-automatic-transmission-work/
http://www.car-engineer.com/the-continuously-variable-transmission-cvt/
https://www.classictoyotatyler.com/blogs/2332/toyota-direct-shift-cvt-tyler/
