What is a CVT Transmission?

“CVT” stands for continuously variable transmission. A CVT transmission uses a pair of variable-diameter pulleys and a belt or chain to provide unlimited gear ratios.

How does a CVT work?

To illustrate, think of a traditional automatic or manual transmission. They’re built with a defined number of gears, for example first through sixth (plus reverse). The transmission can operate in only one gear at a time. You typically feel a slight surge with each gear change.

CVTs, however, offer unlimited gear ratios.

Take a look at the image. You can see the metal belt connecting the two pulleys. Depending on engine speed and load, the computer automatically varies the pulley sizes to ensure the optimal gear ratio for the driving conditions.

CVT Transmission Fluid
CVTs use variable-diameter pulleys to create unlimited gear ratios.

CVT transmission pros and cons

What good does that do?

Imagine pedaling a bike. As you approach a steep hill, you adjust the shifters so a smaller chainring attached to the pedals is driving a larger sprocket on the rear wheel. This reduces the effort required to move the bike.

CVT Transmission Fluid

When you reach a stretch of flat road, you adjust the gear ratio again so a larger chainring attached to the pedals is driving a smaller sprocket. This helps achieve the perfect balance between energy expended and bicycle speed.

CVT Transmission Fluid

The same principle applies to a CVT, except the computer does all the thinking for you. When starting from a dead stop, it varies the pulley diameters (smaller drive pulley and larger driven pulley) so the engine can move the car as efficiently as possible. As you accelerate, it continuously varies the pulley sizes to keep the engine in its “sweet spot,” which results in improved fuel economy. Plus, you never feel the gear engagements because, in effect, there aren’t any.

CVTs gaining in popularity – but there are negatives

These benefits are why many car makers, including Nissan, Honda and Toyota are introducing more vehicles with CVTs.

There are drawbacks, however, including the “rubber-band effect” (you rev the engine, yet it takes a moment for vehicle speed to catch up) and lack of driver involvement (zero fun). In addition, most CVTs’ relatively diminutive parts can’t handle the power and torque of the truck or SUV you use to tow your boat or camper, which is why you find them mostly on smaller cars. Although there are some exceptions, as the list shows, which shows popular vehicles with a CVT.

What cars have a CVT transmission?

  • Honda Accord
  • Honda HR-V
  • Mercedes-Benz A- and B-Class
  • Nissan Altima
  • Nissan Pathfinder
  • Subaru Forester
  • Subaru Impreza
  • Subaru Legacy
  • Subaru Outback
  • Toyota Camry
  • Toyota Highlander Hybrid
  • Toyota Prius

Slip into something special

One look at the guts of a CVT and you can’t help but wonder how the belt doesn’t just slip wildly over the pulleys.

Believe it or not, the transmission fluid plays a major role in ensuring the belt or chain remains in contact with the pulleys without slipping.

That’s why CVTs require specialized CVT transmissions fluids, and not the traditional automatic or manual transmission fluid you probably have in your garage. CVT transmission fluids must be formulated with the correct frictional requirements to guard against slipping. Using the wrong fluid will reduce performance and potentially wreck your transmission.

Wear protection also important

Solid wear protection is also vital to maximizing CVT performance and life. That’s why we designed AMSOIL Synthetic CVT Fluid to fight wear and help extend transmission life.

To demonstrate, we pitted AMSOIL Synthetic CVT Fluid against Nissan NS-2 CVT Fluid in a field trial. After 100,000 miles, the belt lubricated with AMSOIL Synthetic CVT Fluid demonstrated minimal wear, as you can see in the images. This helps you get the best performance and most life out of your CVT.

AMSOIL Synthetic CVT Transmission Fluid

Buy AMSOIL Synthetic CVT Fluid

While driving purists may initially scoff at the notion of a transmission that requires no driver input, many eventually warm up to CVTs’ increased gas mileage and smooth operability.

If you’re one of them, make sure you protect it with a good CVT transmission fluid.

Updated. Originally published Feb. 27, 2017

Comments

  1. Hi! I want to use the Amsoil transmission fluid in my Subaru Forester and I read that the old fluid needs to be completely drained. I am afraid that the person doing this is not going to totally drain the old transmission fluid out before adding the Amsoil CVTQT-EA transmission fluid. What percent of the old fluid needs to be drained before adding the Amsoil?
    Thanks!

    1. Hi Karleen,

      Automotive CVTs have torque converters, so the same adage as a traditional automatic transmission applies (perform three pan drops or a single flush). While there is no specific percentage of old fluid that needs to be removed, every effort should be made to get as much of the old fluid out of the transmission before installing the new fluid. This will maximize the performance and extend the life of the new fluid. However, AMSOIL CVT fluid is compatible with other CVT fluids, so there are no issues mixing with the small amount of residual oil.

      Thanks,

      John

    1. Hi Gabriel,

      AMSOIL Synthetic CVT Fluid is recommended for applications that call for the Nissan NS-3 specification. However, we have no plans right now to perform head-to-head testing against Nissan’s brand of CVT fluid.

      Thanks,

      John

  2. If you use the AMSoil Fluid in your CVT transmission do you still need to get the fluid changed every 30,000 miles as required by Nissan? If you don’t need to change the AMSoil fluid evey 30,000 like you do using the Nissan fluid would your warranty still be good with Nissan?

    1. Hi Sam,

      AMSOIL Synthetic CVT Fluid should be changed according to your vehicle manufacturer’s recommendations. So, in this case, you do need to change it every 30,000 miles. Also, using AMSOIL Synthetic CVT Fluid won’t affect your new-vehicle warranty.

      Thanks,

      John

    2. Hi Matt,

      I suggest you go back and talk to the dealership. Following the OEM guidelines should not void the warranty. Nor does using a non-OEM brand of CVT fluid. Go here for more details.

      Thanks,

      John

  3. I recently purchased a 2018 Nissan Murano. FYI: It has a CVT but Muranos are not on your vehicle list. According to the Owner Manual, NS-3 is the “recommended” fluid. The capacity is unstated. BTW, I really enjoy driving with this transmission.

    1. Hi Grover,

      The list isn’t exhaustive; it’s meant to show some of the most popular vehicles with CVTs.

      Thanks,

      John

  4. Would’ve been nice to see a short cut away video of a cvt “in action”. Although my ’15 Civic has a cvt which works well, what I REALLY don’t like is the 5-10 second delay shifting when its cold/first drive of the day.

  5. I really glad to read this blog, your work is really amazing and the information will definitely useful for me personally, I have many bad experiences with this SVT transmission and now I feel by this blog I can overcome the problems. Is Nissan NS-1 requires for the transmission?

    1. Hi Charles,

      I’m not sure the language Nissan uses in its owner’s manuals, but it’s likely they “recommend” a Nissan-branded CVT fluid. Original equipment manufacturers, however, are prevented by law (Google the “Magnuson-Moss Warranty Act”) from requiring you to use their brand of fluid unless they provide it free of charge. AMSOIL Synthetic CVT Fluid is recommended for applications that call for Nissan NS-1, so rest assured you can safely use it and it’ll work great in your vehicle.

      Thanks for reading.

    1. Yes, AMSOIL Synthetic CVT Fluid is recommended for belt- and chain-type continuously variable transmissions requiring Nissan NS-1, NS-2 or NS-3.

      Thanks.

  6. I had the cvt transmission in a 05 honda civic hybrid and i loved that transmission setup it was perfect combo with the hybrid although wasnt a performance car or the 6 speed si i love so much, it did get great gas milage and was very smooth to drive. If you want smooth driving and great fuel economy than thats a great trans.

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