What is a Continuously Variable Transmission (CVT)?

When you think of a car’s transmission, you most likely group it into one of two categories: automatic and manual. And for the most part, this is the easiest and most accurate way to break it down.

However, in recent years, we’ve seen more and more manufacturers stray from the traditional automatic and manual transmission formula, introducing new options that don’t exactly fit into either category. Some of these designs, like the dual-clutch transmission, have gone on to bridge the gap between the lightning-fast automatic transmissions of today and the engaging manual gearboxes we’re losing more and more of every year. One of these alternatives has caught on more with consumers than the others though; the CVT.

Exposed workings of an Audi CVT transmission
AutoStrong-M, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons

What is a CVT?

One of these transmission solutions that doesn’t fall perfectly into either the traditional transmission classifications is continuously variable transmissions, or CVTs. While regular transmissions, manual or auto, shift between a fixed set of gears each with their own ratios, CVTs have nearly unlimited gear ratios. There are a few different designs used in CVTs by various manufacturers, but today we’ll mostly only be covering the most popular type used in the majority of current CVT offerings.

CVTs are unique compared to a traditional transmission because of their “shiftless” nature. Continuously variable transmissions forgo normal gears and instead generally use a pulley system with a variable diameter steel belt (sometimes referred to as the V-belt). The transmission uses a set of cones to control the diameter, which directly affects the gear ratio of the transmission. 

Chain belt of a CVT transmission
AutoStrong-M, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons

Rather than having individual gears for each ratio, the dynamic belt of the CVT allows for the transmission to be in the optimal ratio for the engine’s output at all times. Instead of shifting between a set selection of ratios, CVTs automatically alter the ratio, using the cones to shift the V-belt to the intended positions. 

History of the CVT

The idea of a continuously variable transmission has been around for ages, with Leonardo DaVinci sketching up the first design for one back in 1490. Daimler-Benz followed this up nearly 400 years later with the first patent on a CVT-style transmission. 

CVTs gained initial notoriety in motorcycle hillclimb racing in the early 1910s, where they would eventually be banned in the name of retaining competitiveness. Subaru would take the reign on popularizing the CVT in the 80s, and other automakers would quickly follow suit.

Benefits of the CVT

Continuously variable transmissions have become increasingly popular among commuter vehicles. Most major automakers employ a CVT on at least one of their models. What makes them such a proposition for these brands?

Optimize Fuel Economy

One of the primary benefits of a CVT is increased fuel efficiency as a result of the dynamic gear ratio. As the belt is continuously moved based on the engine’s RPM, it’s able to stay in the optimal range for power and efficiency.

This allows for CVT vehicles to be some of the most fuel-efficient on the road, keeping engine speed low and maximizing the drivetrain’s ability to use the power produced by the motor. 

Smooth Acceleration/Deceleration 

Anyone who’s driven a car with a traditional gearbox (especially an older one) has experienced the slight jolting feeling that comes with changing gears. One of the biggest benefits of a continuously variable transmission is its “step-less” or “shiftless” design, eliminating the need for the usual gear changes that disrupt smooth power delivery. 

Lower Production Costs

While not a benefit that affects us directly for the most part, the decreased production costs for manufacturers have been another driving force of CVT adoption. Due to their simplified design and fewer moving parts, CVTs can be produced at a lower price point and that difference can be reflected in the final price of the vehicle. 

Downsides of the CVT

Increased Maintenance Costs

The decreased cost of production may bring the price down for consumers initially, but repairs on CVTs can often be a bit more expensive than traditional gearboxes due to the unique components they require and the additional training of the technician servicing them. 

CVTs also experience quicker failure, as the components wear down at a higher rate. Some continuously variable transmissions have been known to fail around the 100,000-mile mark, whereas many traditional transmissions last over double that. 

Driver Feedback

While not a drawback in any quantifiable metric, many CVT drivers report having trouble adapting to the unique driving experience and droning noise of these vehicles. Without the sensation and sounds of shifting gears, the powertrain doesn’t produce much noticeable “feedback” during acceleration or deceleration and can leave the driver feeling disconnected from the vehicle. 

The gradual RPM increase and the monotonous drone of the exhaust can take away from the experience of driving an internal combustion vehicle. Many consumers complain that CVTs eliminate the “rhythmic” sensations and sound from the engine and transmission that many drivers rely on to feel confident and comfortable behind the wheel. This problem is exacerbated in performance vehicles like the Subaru WRX, a segment where the feedback of the powertrain and engaging feel are so essential for many driving enthusiasts. 

This isn’t to say this learning curve can’t be adapted to fairly quickly, but this odd driving feel has been cited as one of the main reasons some consumers refuse to take their chances on a CVT vehicle. 

Horsepower Limitations

CVTs aren’t a popular choice for sports cars for a few reasons, such as the feedback issue we covered above. However, the biggest roadblock for these transmissions in performance vehicles is their inability to handle high horsepower. 

This is mainly a result of their construction, as the variable belt and cone combination run into problems with power outputs much higher than an average grocery-getter. CVTs may eventually turn into a prime choice for performance cars due to their optimized power delivery and efficiency, but for the time being, they’re mostly relegated to commuter vehicles until more durable versions are developed. 

Is a CVT Right For Me?

The answer to this question comes down to personal preferences and the intended purpose of the vehicle. CVTs bring some great benefits to the table, but their downsides make them impractical in some circumstances in their current form. 

If you’re interested in maximizing your fuel efficiency for commutes and errands, CVT vehicles can be a great choice (provided you can get used to the unique experience of driving one). These vehicles often offer some of the highest MPG and smoothest driving experiences on the market and will continue to make their way into more new vehicles for good reason.

A CVT is probably not right for you if you value feedback from your engine and/or the ability to tune the vehicle to a higher power output. We recommend extensively test-driving any CVT vehicle before you buy it to ensure you aren’t too bothered by the monotone sound and stepless acceleration that comes with one. 

CVT & Transmission Services in Tucson

If you’re looking to have your CVT or traditional transmission services, look no further than the experienced import vehicle technicians at Micro Import Service in Tucson, Arizona. Our team has extensive training on all types of transmissions and will return yours to the proper condition! Most Asian import brands use CVTs in some form, including Honda, Nissan, Toyota, Subaru, and others. Finding the proper repair facility for these unique transmissions is crucial to keeping yours maintained and operating at its best. 

Call or schedule online with us today and chat with our friendly service advisors about the perfect maintenance plan for your vehicle.