Useful Tips on Driving Cars Equipped with CVT Transmissions

Continuously Variable Transmissions (CVTs) have been around for quite a long time, but for some drivers this type of transmission still remains a mystery. CVT transmissions have certain design peculiarities, which have a significant impact on rules of operation of these units. In this article, we will consider the main aspects of driving CVT-equipped cars and learn how to avoid early visits to repair shops.

First of all, CVT transmissions significantly differ from other automatically-shifted transmissions (standard automatics or dual-clutch transmissions) in terms of design. Thanks to its design features, this transmission ensures smooth shifting without jolts, delays, or slippages. A car with this transmission accelerates easily without jerks, which to some extent can be experienced when driving cars equipped with automatic or dual-clutch transmissions. Other advantages of CVTs also include fuel efficiency (compared to automatic transmissions), better load distribution on the engine and transmission, which allows not to overload the transmission and to increase its service life.

Taking into account all advantages of CVTs, it may seem that this type of transmission can easily replace a conventional automatic transmission on the automobile market, but that’s no entirely true. The thing is that that many drivers with the experience of driving a CVT-equipped car complain about a noticeably smaller operational resource of CVTs compared to automatic transmissions, low maintainability of CVTs, high repair costs, and a wide range of limitations during operation.

Design basics of CVT transmissions

When it comes to design, CVT transmissions are quite simple. The structure of this type of transmission is based on two sliding pulleys. One pulley is connected to the engine, while the second one is attached to the driving wheels. The pulleys operate with the help of a special belt (or a chain). Each pulley is V-shaped, and its halves can smoothly converge and diverge. When both halves diverge, the belt (or chain) goes to a smaller radius, and at the converging stage the belt starts operating at a larger radius. The role of the clutch is performed by the torque converter or by the pack of disks, operating in the oil bath.

Learn more about a CVT transmission and its principle of operation

More advanced CVT solutions can emulate the operation of a traditional automatic transmissions – the control software forces the pulleys to converge and diverge not smoothly (as in standard CVTs), but in steps. Such a transmission shifts as an automatic transmission, making a driver to feel more comfortable when driving. This concept was successfully implemented in Lineartronic CVTs used in Subaru models.

Peculiarities of driving CVT-equipped cars

Despite numerous debates about its operational peculiarities and repairability characteristics, the CVT transmission technology has already gained popularity on the automobile market and some manufacturers of transmissions, such as Jatco, have high hopes for this type of transmission. At the same time, it is necessary to bear in mind that owners of cars have to comply with particular operation rules, which stem from CVT design peculiarities.

Cross-section JF011E- one of the most popular CVT units on the market

High Loads and Warm-up necessity

First of all, it is necessary to understand that CVT transmissions are not intended for high loads. To put it simply, when starting off the car equipped with the CVT transmission, you have to accelerate smoothly, gradually raising the engine speed. Otherwise, you’ll face CVT problems very soon. In practice, there are many cases when owners of CVT-equipped cars, who like rapid accelerations from traffic lights, started having transmission issues after travelling only 50-60 thousand kilometers. In addition, it is strongly recommended to warm up the CVT unit in cold weather. CVTs require sufficient lubrication (oil starvations are damaging for CVTs). At low temperatures transmission fluid distribution takes more time. It should be noted that CVTs cannot be warmed up the same way as conventional automatic transmissions (engaging all gears with a few seconds delay), as CVTs constructively differ from hydromechanical automatics. When it comes to the CVT warm-up, firstly it is necessary to warm up the engine and to engage the N gear for a few seconds. Then, you can start moving, at the same time minimizing the load on the transmission unit during the first 3-5 kilometers. It the temperature drops to -30 °C, then it is better to refrain from driving a CVT-equipped car.

Maneuvering and cornering

When driving a car equipped with a CVT, do not forget that this type of transmissions is very sensitive to increases of the engine RPM rate. In practice, first of all drivers increase the RPM rate by pressing the gas pedal, then the transmission control system will flexibly change gear ratios in accordance with the engaged gear and ensure that the engine operates in the most efficient manner. But this adjustment takes some time. If you make a maneuver while driving, you have to bear in mind the abovementioned peculiarity of CVTs operation. First of all, make sure that you achieve the necessary RPM rate and then perform a maneuver. The same applies to cornering: you have to press on the gas pedal at the moment when starting to turn the steering wheel.

Off-roading

CVTs are generally not intended for regular off-road use. Even if you are an owner of the SUV equipped with the CVT transmission, you should not get carried away with off-roading. Otherwise, you can easily damage the transmission getting into a road hump. If the mechanical damage occurs in the transmission unit, you may have to deal with serious consequences: from fluid leakages to the breakdown of main components. In any case, reckless off-road driving will result in costly repairs. The wheel slipping also can lead to rapid wear of CVT components. If you get stuck in dirt or a snowdrift, it is not recommended to try to get out of trouble by frequently shifting between D and R gears.

Transportation and towing

Passenger cars and SUVs equipped with CVTs are poorly adapted for towing and transportation of heavy loads. For this reason, it is not recommended to use a CVT-equipped car for towing of other cars; otherwise, it may lead to rapid wear of transmission components and complete damage of the unit. If the car manufacturer allows towing, be sure to examine its peculiarities in the manual. But in practice, towing of other cars leads to the transmission damage, especially when it comes to “old” CVTs. As for driving with a trailer, it is important that the trailer weight does not exceed permissible limits specified in the car manual. There may also be limitations on speed and distance to be travelled when using a trailer. If your car broke down in the middle of the road, it can be towed over short distances with the running engine. If the engine does not start, then towing can be performed only when the axle shafts are disconnected from the drive wheels. But ideally, in such cases it is desirable to call a tow truck in order to avoid additional risks.

Great video from Engineering Explained on things you should never do when driving a CVT-equipped car

CVT maintenance

When it comes to CVT maintenance, the main point is the transmission fluid status. It is critical to regularly check fluid condition and its level. CVTs operate with special types of transmission fluid ensuring lubrication of the interacting surfaces and preventing slippages. CVT fluids must be changed more often than in automatic transmissions. It is also recommended to use CVT fluids specified by the car manufacturer. According to manuals, it is necessary to change CVT transmission fluid once every 60 thousand kilometers, but in practice it is desirable to perform this procedure every 30-35 thousand kilometers.

If we talk about possible failures of electronic components, it is necessary to pay close attention to the state of separate EECS sensors. Problems with these sensors may lead to additional loads on the CVT unit, resulting in its failure. Constant monitoring of sensor operating condition is a must. One faulty sensor can lead to the failure of the whole unit. If the speed control sensor is damaged, the control unit automatically switches the transmission belt to the emergency position, the engine starts braking urgently. In this case, there is a high risk of the belt deformation (or even its damage when driving at high speeds). For those who buy a used car equipped with the CVT transmission, the first thing to do is to replace the speed sensor (it is desirable to buy the original part from the manufacturer). The same applies to oil level and pressure sensors. The entire set of sensors must be in good operating condition.

Summary

To sum it up, it can be assumed that CVT transmissions can ensure more comfortable and fuel efficient driving compared to classic automatic transmissions. However, it should be borne in mind that this type of transmission is not intended for high loads and severe conditions (overheating is lethal for CVTs). To put it simply, CVT-equipped cars are more suitable for the use on good urban roads and for drivers with a calm driving style (without abrupt starts, slippages, frequent overtakings).

To keep the CVT transmission in perfect operating order you have to do the following:

• Ensure timely maintenance servicing;
• Monitor transmission fluid level and its condition;
• Warm-up the transmission before taking off;
• Avoid excessive loads.

When complying with these rules, your CVT transmission will accurately operate during the entire service period specified by the manufacturer.