A continuously variable transmission (CVT) Pross & Cons

Administrator posted this 06 June 2019

The mechanism and technology of transmission have evolved over centuries, and was used by ancient civilizations. However, in this article we will focus on a modern car transmission, it will disperse the question of what is CVT transmission its characteristics, advantages and the CVT transmission troubleshooting help.

What is a CVT

Continuously Variable Transmission, briefly CVT, is a stepless gearbox, the peculiarity of which is that the usual in the understanding of the classical transmission automatic transmission is absent in this case. In its construction, it uses pulleys and a belt or chain to transmit engine power to the driving wheels. A vehicle with a continuously variable automatic transmission gains speed more evenly and smoothly, while the efficiency increases slightly. Due to its mechanism, this type of transmission optimizes engine performance and fuel efficiency. Uninterrupted gear shifting allows you to achieve stable engine the RPM at different vehicle speeds. A brief historical journey to the invention and implementation of CVT, will allow for a more expedient understanding of the principle of its operation.

History of automobile transmission

Although, as mentioned at the beginning, the first transmission mechanism was used in ancient times, namely for water mills, the invention of the transmission is attributed to Leonardo da Vinci. Artist, inventor, engineer and scientist Leonardo da Vinci designed various gear and transmission systems for his machines. Then the first manual transmission was patented by French automobile industry pioneers - Louis-René Panhard and Émile Levassor. After 27 years, the compressed air automatic transmission was invented by the Canadian engineer Horner Munro. The mass implementation of a hydraulic transmission (Hydra-Matic) was started in 1939 in the production of General Motors cars. Since the 1950s, the automotive industry has been actively developing, and modern cars even offer AI-driven electronic shift control systems. However, CVT has not lost its relevance, and to answer the question: "Are CVT transmissions bad?" let's compare it with other solutions.

CVT comparison and characteristics with other transmissions

The comparison of CVT vs. automatic and mechanical transmission systems will allow you to choose the most relevant for the driver car, which will match the purpose and style of driving. Especially, such a comparative table will be useful for novice motorists.

Features	Continuously variable transmission	Manual transmission	Automatic transmission (traditional)
Mechanism	Uses a belt or chain and pulley system.	Uses a fixed set of gears for manual shifting.	Uses planetary gears and a hydraulic torque converter.
Operation	Continuously adjusts gear ratios for smooth power delivery without distinct shifts.	Driver manually controls gears using a clutch pedal and gear lever.	Shifts gears automatically based on engine speed and throttle input.
Types	Belt or chain driven IVT or toroidal CVT Hydrostatic CVT Cone CVT eCVT	5-, 6- 7-speedmanual transmission Floor shifting manual transmission AMT SMT (sequential manual transmission) Synchronized manual transmission	Traditional AMT Dual-clutch transmission CVT Triptronic
Efficiency	Higher fuel efficiency than traditional automatic.	Depending on driving habits, the highest fuel efficiency can be reached.	Less efficient than CVT.
Driving	Flexibility for a powertrain, speed of an engine without the jolting shifts, Seamless driving.	Full driver control, required higher driving skills.	Smooth and effortless.
Performance	Smooth acceleration, better engine RPM control.	Depending on driving habits, the best performance control and power delivery can be reached.	Good for smooth acceleration but sometimes slower gear changes.
Cost	Expensive than manual, cheaper than automatic	The cheapest among offered	More expensive among offered
Maintenance	More expensive to repair, durability is lower than a traditional automatic.	Cheap and easy to maintain by any service shops	Also, expensive repair but also a long service life.
Model type compatibility	Common for hybrids, economy cars, and some crossovers, but not a must	Common for sports cars, budget vehicles, and commercial vehicles, but not a must	Common for sedans, SUVs, luxury cars, and trucks, but not a must
Examples	Toyota Corolla, Honda Civic, Nissan Rogue	Mazda MX-5, Ford Mustang, some Volkswagen Golf	Toyota Camry, BMW 3-Series, Ford F-150

CVT vs. regular transmission demonstrates that the simple manual transmission is still used for profound driving experience in sports cars and in budget vehicles. On the other hand, the CVT has some advantages against classic manual transmission.

Is CVT better than automatic? It depends on the specific needs of the driver. As you could see from the table CVT is indeed a type of automatic transmission, but it operates differently. Simply to say traditional automatic offers convenience and smooth performance, while the CVT offers fuel efficiency and smooth driving.

The CVT itself is represented as two pulleys interconnected by a belt or chain. One pulley is connected to the input of the transmission, and the other one is connected to the output. The second pulley is responsible for transmitting torque to the driving wheels of the car. The position of the pulleys, and accordingly the belt, resulting gear ratio.

The effective gear ratio decreases when the diameter of the input pulley is larger and the output pulley is smaller. This happens because the belt (chain) moves to a lower position on the input pulley and higher on the output.

The effective gear ratio increases when the diameter of the input pulley is smaller and the output pulley is larger. This happens because the belt (chain) moves to a higher position on the input pulley and lower on the output.

In conclusion, this dependence explains what does CVT transmission stand for.

Advantages of CVT

For further consideration, continuously variable automatic transmission will examine the advantages and propagation of CVT transmission issues.

The advantages of the CVT in a car:

Smooth and dynamic acceleration (compared to traditional automatic transmission and manual gearbox)
Enhance fuel consumption efficiency
No shocks when changing gears
Unlimited gear ratios for various driving conditions.
Efficiency in comparison with automatic transmission is higher by 5%
Easy driving control
Efficient use of engine power and torque
Simplified transmission design, fewer parts involved and less weight

When choosing a transmission, it is sometimes more important to pay attention to CVT transmission problems.

The disadvantages of the CVT in a car:

Complex system management, and configuration of powertrain electronics lead to high expenses of maintenance
The care variable is also costly (e.g., motor oil and only high premium)
The CVT is not suitable (not desirable) for sports cars and powerful cars, in general

CVT troubleshooting - diagnostic trouble codes

Cars might face with CVT transmission problems. Transmission generates OBD2 DTCs if there are related issues with workflow or components. There are about 1,086 CTV errors, of which 704 belong to the Powertrain group (P-codes), 83 to the Chassis group (C-codes) and 299 to the Network Communication group (U-codes). However, there are common error codes that can be detected by a simple scanning process using your smartphone and inCarDoc app.

P0700 Transmission Control System Malfunction
P0715 Input/Turbine Speed Sensor Circuit Malfunction
P0720 Output Speed Sensor Circuit Malfunction
P0740 Torque Converter Clutch Circuit Malfuction
P0760 Shift Solenoid C Malfunction
P0868- Transmission Fluid Pressure Low/High

When you scan the OBD2, the mobile application will provide decoding of the found errors. You can clear them by saving the log of this check for further monitoring of systems.

Are CVT cars is good?

We have examined in detail and characterized continuously variable automatic transmission. Whether this type of transmission is suitable for your type of driving is up to you. You can use the comparison of the difference between CVT and automatic and manual transmission. We hope this article was useful for you. For easier and safer driving, use the OBD2 scanning tool - inCarDoc