Pros and cons of buying a car with a CVT transmission
Updated: August 29, 2021
Many modern cars use a continuously variable transmission or CVT for better fuel economy. The CVT technology is clever and simple, but has its drawbacks. Let's look at the pros and cons and see how the CVT works. Here, we are only talking about the mechanical CVT with a variator
; the electronic CVT used in hybrid vehicles is completely different and is not covered here.
The key component of the CVT is a variator.
It consists of a chain or steel belt running between two pulleys. Each pulley is made of two cones facing each other. The working surface of the cones is smooth. The size of each pulley can be changed by pushing the cones towards or away from each other using hydraulic pressure. The hydraulic pressure is generated by an oil pump.
Take a look at this Audi CVT in the illustration above. The engine runs the pulley set 1. The pulley set 2 is connected via a differential to the drive wheels. Right now the cones of the pulley set 1 are pulled away from each other, while the cones of the pulley set 2 are squeezed together. This equals to the low (1-st) gear in a regular transmission. As the vehicle accelerates, the transmission "upshifts" by gradually increasing the size of the pulley set 1 and reducing the size of the pulley set 2. See the CVT gear ratio illustration below.
Are CVT Transmissions Good for Towing?
CVTs work well in small and medium cars and SUVs and are better suited for fuel-efficient city driving and moderate load. If you plan on using your vehicle for towing a trailer, a conventional automatic transmission with a fixed number of gears is a better choice.
Do CVT transmissions require more maintenance?
The only maintenance requirement for a CVT transmission is changing the CVT fluid, which is not very expensive. Many manufacturers don't even list CVT fluid changes in the maintenance schedule for normal driving conditions. Instead, they advise changing the CVT fluid if the vehicle is operated in severe driving conditions, including towing, driving on dusty or muddy roads, or in freezing or very hot temperatures, etc. Mechanics, however, advise changing the CVT fluid more often. If you want to keep the CVT fluid fresh, you can have your dealer check the fluid and change it if needed. For example, the owner's manual for the 2017 Nissan Maxima says: ...request the dealer to inspect the
fluid deterioration data using a CONSULT. If the
deterioration data is more than 210000, replace
the CVT fluid.
Pros and Cons of a CVT transmission
High and Low gear ratio in the CVT transmission.
The main advantage of the CVT is better fuel economy, especially in city driving. A vehicle with a conventional automatic transmission loses some of the momentum while shifting from one gear into another. CVT has no fixed gears. It changes the gear ratio seamlessly without losing the momentum. It also has fewer moving parts.
One of the main drawbacks of the CVT is its limited torque capacity. Because the surfaces of the cones are smooth, the cones have to squeeze the belt or chain with great force. If an engine has too much torque, the belt or chain might slip.
Manufacturers are working on ways to increase the torque capacity of the CVTs, but for now it's still limited. This is why you don't see CVTs in pickup trucks and muscle cars, as their engines have much more torque. Auto makers program CVT computers to keep it in the "lower gear" longer on acceleration. This reduces the load on the CVT variator. That's why many reviewers often mention louder engine noise and slower acceleration of the CVTs.
Another minus is that CVTs are expensive to replace. The CVT unit replacement can cost upwards of $4,000 in some cars.
If you need a car for long commutes, towing or sporty driving, a conventional automatic transmission is a better choice. Of course, many sports car enthusiasts prefer a manual gearbox.
Are CVT transmissions reliable?
The number of CVT complaints varies not only between manufacturers, but even between different model years of the same car. For example, the quality of Nissan CVTs has not been consistent. We have seen some of the early Nissan Murano SUVs still going with over 200K, but some other models had problems. For example, according to CarComplaints.com, the 2013 model year saw a spike in CVT problems for Nissan Altima.
Chrysler and Mitsubishi also had problems with their CVTs in some model years. Mitsubishi did a recall for CVT issues, read more in this CNet article
Honda also issued the recall 15V-574 for the 2014-2015 Civic and 2015 Honda Fit.
Subaru CVT display.
Subaru has extended the warranty for their CVTs for some models, read more in this Forbes article
On the other hand, there are not that many complaints about the CVT in the 2014+ Toyota Corolla or 2014+ Honda Civic, for example.
Considering all that, the reliability of CVT transmissions should be judged on a case by case basis.
Where can you check the reliability of a particular used car model?
- to access their ratings online, you will need a paid subscription. You may also find a printed copy of their car buying guide in the book store or local library.
- follow the Vehicle Owners menu and then Search Safety Problems. If you compare the number of complaints from one model year to another, it's easy to see the model years with the most problems.
- you can also see the model years to avoid.
Another life hack is to check the vehicle's trade-in value. What will it tell you? Dealers know which car is good, and which has many problems and they set the trade-in value accordingly. Check the trade-in value at KBB.com
and if it's very low compared to similar cars, you know the car should be avoided.
Is there a way to extend the life of a CVT?
Many CVT transmission problems are caused by overheating. For this reason, many automotive enthusiasts recommend upgrading the CVT fluid coolers to keep the fluid from overheating. This is even more important if you like spirited driving or use your car for towing. There are many YouTube videos
on this subject.