A Continuously Variable Transmission (CVT) is a transmission that can change seamlessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT allows the input shaft to maintain a constant angular velocity.
A CVT usually has a low efficiency of 88%, but it can provide a gear solution that enables the engine to run at its most efficient revolutions per minute (RPM) for a range of vehicle speeds. This allows the vehicle to have an acceptable fuel efficiency.
Alternatively, it can be used to help maximize the performance of a vehicle by allowing the engine to turn at the RPM at which it produces peak power. This is typically higher than the RPM that achieves peak efficiency. Finally, a CVT does not strictly require the presence of a clutch.
The Nissan® Versa® (SL and SV models), Versa NOTE® (S Plus and higher), cube®, JUKE®, Sentra®, Altima®, Maxima®, Rogue®, Murano®, Pathfinder®, Quest® and Infiniti JX/QX60 all have a CVT.
Nissan CVT technology uses only one input from a prime mover and delivers variable output speeds and torque; whereas Power Split Transmissions (PST) technology uses two prime mover inputs and varies the ratio of their contributions to output speed and power. These transmissions are fundamentally different.
The CVT is a technology Nissan continues to refresh and modernize. Today, the virtually gearless Xtronic® CVT makes gear hunting a thing of the past. Fully variable gear ratios mean the CVT can hold the engine at the ideal RPM. CVTs are included on vehicles across Nissan’s diverse and growing lineup.
Next-generation Xtronic CVT®
The 2013 Nissan Altima was the first Nissan equipped with the next-generation Xtronic CVT. The dramatically improved technology achieves a significant 15% increase in fuel efficiency, accelerates faster, runs quieter and offers an even more seamless shifting experience.
Xtronic CVT
The Next Generation Automatic Transmission.
Traditional automatic transmissions have five, six or even seven gears. The more gears you have, the better the transmission, or so the story goes, but not anymore. Nissan’s CVT does not have traditional fixed gear ratios. Instead, it uses an ingenious steel belt/pulley system to move up and down the gear ratio in a continuously smooth motion. The elimination of the gears helps get rid of the friction that typically occurs during shifting. Less friction means more efficiency.
Increased Gear Ratio
Imagine that the CVT is like a bicycle’s gear system. It is made up of a pulley system with cones at each pulley, which are all connected by a chain belt. These cones move closer together or further apart to increase or decrease the diameter at which the belt operates. The ratio here is important and is selected automatically based on factors like gas pedal position, vehicle speed and engine speed. What all this means is that a CVT does not shift at all like a traditional gearbox. The ratios are always changing in order to find the best possible combination for speed, fuel efficiency or both.
Improving Customer Perception of How CVTs Operate
Stuck in a Single Gear?
Because the CVT is different than a traditional automatic transmission, it sounds different than a traditional automatic transmission. CVTs have no fixed gears so the engine RPM does not rise and fall as the transmission works through the stepped ratios. To an unfamiliar driver, a car with a CVT can sound like it is stuck in one gear. It emits a distinctive, almost “high-tech” sounding single transmission tone that changes pitch as the transmission cycles up and down the gear ratios. It does not gear hunt and does not give a shift shock since the power is supplied seamlessly through acceleration to move through the gear ratios in a continuously smooth motion. When they step on the gas pedal, customers will notice that the engine will jump to the needed engine speed and stay there while they accelerate.
