When you're car shopping, you may run across the phrase "continuously variable transmission" or CVT. Why might you choose a CVT versus a conventional automatic transmission?
Some drivers believe a CVT provides a smoother experience compared to a traditional automatic transmission or a manual transmission. But the biggest advantage is that they're more fuel efficient than a conventional automatic; this is why you've seen automakers put them in dozens of models in the past decade.
Compare the pros and cons of a CVT vs. automatic type of transmission and make the better choice for your needs.
How Manual vs. Automatic Transmissions Work
When you're driving a car with a manual transmission, such as a sports car or vintage vehicle, you use the stick shift on the car's console or steering column to maneuver between transmission gears, while simultaneously using your left foot to depress the clutch pedal. Gears are numbered from one to as many as seven, plus a single reverse gear. As the engine's revolutions per minute (RPM) increase or decrease, you shift to the next highest gear or next lowest gear. This continues to match an appropriate engine speed with the vehicle's speed as it accelerates or decelerates.
You work less when driving an automatic transmission car. The transmission shifts on its own; you simply select Park, Neutral, Reverse or Drive and the transmission does the rest. It matches the engine and road speeds automatically.
Automakers build automatic gearboxes with a wide range of gears; older models have as few as three while more recently some brands have patented transmissions with 11. This allows the engine to operate at the most appropriate speed as it relates to the vehicle speed, ensuring the best fuel economy.
In recent decades, vehicles with conventional automatic transmissions have gained wide popularity over manual transmissions in the U.S. Automatic transmissions make learning to drive easier, require less attention when driving, and create less engine wear and tear.
How a CVT Works
Unlike conventional automatic transmissions, continuously variable transmissions don't have any gears. A CVT uses two cone-shaped pulleys. One pulley is connected to the engine and the other is connected to the rest of the transmissions. A steel or composite belt connects the two pulleys.
The pulleys change widths depending on how much power the wheels need from the engine. As one pulley gets larger, the other gets smaller. This design enables a CVT-powered car to accelerate with strength and smoothness.
Variations on CVTs
CVTs are not all the same. One variation is a different, less common CVT style using rollers and discs.
Because CVTs don't have any gears, they don't shift at the common times that an automatic will when the vehicle is accelerating. This lack of shift points can be unnerving for drivers and passengers used to the behavior of a common automatic. To combat this, many brands that rely on CVTs have programmed into their behavior artificial shift points that give drivers the feel of transmission shifting.
The Subaru Ascent SUV is one example (among many) that have this feature. The Ascent features eight preset shift points on the pulley system making it seem as if the car is shifting gears. Drivers either click on paddles mounted on the steering wheel or move the shift lever.
Other models with CVTs have a conventional first gear like normal automatics and then a CVT handles the rest.
Called a “launch gear," this actual gear controls the car's initial acceleration; the transmission switches to the continuously variable transmission mode at 25 miles per hour.
The 2019 model year Toyota Corolla Hatchback has this setup and Toyota says it enables the car to achieve stronger and smoother acceleration from the start.
Pros of CVT vs Automatic Transmission
A key benefit of the CVT is its ability to change its gear ratio continuously as the engine speed changes. This means the engine is always operating at its peak efficiency.
A CVT draws top engine power from a small engine, which gives drivers quicker acceleration than standard automatic transmissions.
Because of their greater ability to control the engine speed range, CVTs produce fewer emissions. CVTs are also lighter weight than traditional automatic transmissions. You get better fuel economy, especially in city driving.
As for the driving experience, some drivers comment that the CVT car ride is extremely smooth compared to normal automatic transmissions. They like that they notice RPM or engine speed changes only when the car is cruising or accelerating.
Cons of CVTs vs. Automatics
Some drivers miss the engine shifts and acceleration of the traditional automatic transmission experience. There's no sound or sense of running through the gears as with conventional automatic transmissions. Although the engine maintains its high speed, you hear only a humming or droning sound. Because a CVT may keep an engine running at higher RPM when an automatic would have shifted to a higher gear, CVT-equipped vehicles can make it seem like the engine is droning loudly under hard acceleration.
Servicing a CVT is different from servicing an automatic transmission. CVTs need special oil, transmission fluid, and parts. You have to take a CVT-equipped vehicle to a service department with a mechanic skilled in transmission repair and maintenance for this type of transmission. Owners of CVT-equipped vehicles find transmission repair is more expensive for them compared to automatic transmission repair or replacement.
Other common problems CVT-equipped vehicle owners report include the occasional sudden loss of acceleration and overheating. Drivers complain of jerking, slipping, and shuddering. CVT belts can suffer excessive stretching and wear. Some owners have experienced transmission failure. Lawsuits against car makers claim the equipment performs unreliably.
Vehicles Using CVTs
Japanese automakers use CVTs more than European and domestic car makers. Mitsubishi, Subaru, and Nissan were particularly early and eager adopters of CVTs and the brands feature them in most, if not all of their cars and SUVs, including the Nissan Altima and the Nissan Murano.
Toyota and Honda now include CVTs in more models, including the latest generations of Honda Civic and Honda Accord. Other CVT-equipped vehicles include Honda CR-V, Honda Accord, Nissan Rogue, and several Mitsubishi models. Domestic cars featuring CVTs include the 2011 Ford Fusion Hybrid.
To find out which type of transmission is in a particular car, check the automaker’s website or a printed vehicle brochure. If it's a new vehicle, look at the window sticker. Used cars may require more product review research.
Which is best for you
Choosing between a CVT vs. automatic is a matter of personal taste. You might prefer the road feel of the conventional automatic transmission. If maximum fuel economy matters, you might prefer the CVT.
Do your research and above all else -- take a test drive to decide what's right for you.