The CVT gearbox is fuel efficient and smooth, why people who know cars don t like it

At present, there are generally three types of automatic transmissions in automobiles, namely AT transmission, dual-clutch transmission and CVT transmission. Among them, the CVT gearbox is also known as the continuously variable gearbox, which is different from the transmission mode of the AT and dual-clutch gearbox, and it is transmitted by steel belt. Both the ride and fuel economy are better than the other two transmissions.

It is said that the CVT gearbox is fuel-efficient and smooth, why people who understand cars don't like it, let's find out together!

The advantages and disadvantages of CVT gearboxes are very obvious, and the biggest advantage is good ride and smoothness. Therefore, many models that focus on comfort will use CVT transmissions, such as Nissan Sylphy, Honda Civic, Nissan Teana, etc. But whether there are two sides to everything, having outstanding advantages must also correspond to disadvantages.

Compared with AT and dual-clutch transmission, CVT transmission has the following two main disadvantages, and it is precisely because of these two shortcomings that many old drivers who like to play with cars do not like models equipped with CVT transmission.

The first disadvantage is the weak affordability.

In order to have good ride comfort, the CVT gearbox adopts a steel belt drive, which uses the friction between the steel belt and the taper pulley to transmit power. Just like the tape of a radio in the past, the friction between the tape and the bearing drives the other bearing to rotate, and if one bearing gets stuck in something, the tape will slip if the force is too large. Today's high-capacity CVT gearboxes can only withstand a maximum of 400 Nm.

If a car has a displacement, it is easy to slip when using a CVT gearbox. Therefore, people who generally understand cars will not choose models with large displacement and CVT gearbox.

The second disadvantage is that it is easy to overheat.

Since the CVT transmission is driven by steel belt friction, the heat generated will be much greater than that of the AT transmission and dual-clutch transmission. Although both dual-clutch and AT transmissions experience overheating of gear friction, it is much less severe than that of CVT transmissions. Generally, the user manual of the vehicle equipped with the CVT transmission states that if the transmission temperature is too high for a long time and the transmission temperature is too high, the transmission automatic protection mechanism will be triggered, and the speed will be limited to 70-80 kilometers per hour.

Among them, the Honda Civic, which is known as "every second and every second", as long as it drives fiercely for more than 20 minutes, the gearbox is likely to have an overheating alarm.

Finally, the CVT gearbox is simpler in structure and lower in manufacturing cost than the AT gearbox and dual-clutch gearbox. This is not considered to be a disadvantage of the CVT gearbox, it is precisely because of the low manufacturing cost that the vehicle ** will also decline. I think if you only have a budget of about 150,000 yuan, choosing a model with a CVT gearbox can indeed experience the smoothness and fuel economy it brings to you.

When buying a car, pay attention to the fact that these CVTs have these two tricky drawbacks in addition to being fuel-efficient and smooth!

Because although he is fuel-efficient and smooth, he is prone to problems while driving.

The CVT gearbox is relatively easy to thermally protect, and after a few hours of continuous driving on the highway, the gearbox will enter a protection mode, and no matter how you refuel the throttle, it can only drive for about 70km h at the fastest.

Because it is prone to some other problems during driving.

The application time is not long, and the maintenance cost is high.

There is often an abnormal noise from the fuel tank, which will be uncomfortable.

The driving experience is poor, and it is useless to save fuel and smooth.

Because I don't have that comfortable feeling when driving.

Fuel saving also brings a lot of bad problems.

Because it's always easy to get hot, it's very unsafe.

Because its disadvantages are greater than its advantages.

CVT gearbox is fuel-efficient compared to AT gearbox, which is mainly reflected in the premise that the speed in the city is not fast, and the driver is more Buddhist driving habits, but CVT has many shortcomings, not only the starting speed is slow and the failure rate is much higher than that of AT gearbox, the steel belt is easy to slip for a long time, and at the same time, because the torque is small, it is not suitable for models with large horsepower, and the gearbox is easy to heat up in the case of high speed and long-term driving, and the fuel consumption is not much lower than that of AT gearbox when driving at high speed for a long time. Many of the current AT gearboxes use 8AT, 9AT and even 10AT gearboxes, and the fuel economy is not much different from CVT, but the AT gearbox is stable and not easy to fail, and can match high-horsepower engines. Therefore, the AT transmission is still the mainstream in the automatic transmission model.

The CVT gearbox is more fuel-efficient than the traditional AT gearbox. Its advantages are fuel saving, environmental protection, good adaptability of Shuliang section, low cost and no slag shed, lack of dry point is lack of driving fun, slightly poor stability, transmission loss, and high maintenance costs.

Yes, it is fuel-efficient, because it is a continuously variable speed, you can keep the engine in the most suitable output range at any time according to the needs of the vehicle. Advantages: The power output of the CVT gearbox is linear, and the sedan is very smooth in actual driving.

Cons:The steel belt of the CVT transmission is limited in its ability to withstand the force.

I think it is really fuel-efficient, the advantage of this gearbox is that the structure is relatively simple, the cost is low, the disadvantage is that the carrying power is relatively small.

In terms of the type of automatic transmission, both CVT transmission and dual-clutch transmission are more fuel-efficient. But the fuel consumption of an AT transmission depends on what the AT is. For example, the fuel consumption of the previous 4AT and the current mainstream 6AT is higher than that of CVT, but the fuel consumption of 8AT and 9AT is about the same as that of CVT.

This is due to the structure and working principle of the transmission. At the front end of the AT gearbox, there is a component called the torque converter, which is used to disconnect and connect the transmission of power. Its internal pump wheels and turbines are driven by liquids.

It has the advantage of being rough and has a good cushioning effect when changing gears. Its disadvantage is that the speed of the pump wheel and the turbine is not synchronized, resulting in the loss of power, so the transmission efficiency is relatively low. After the efficiency is low, the fuel utilization rate will decrease, and the fuel consumption will be relatively high.

Even with some advanced AT transmissions, the torque converter will lock up at fast speeds, and fuel efficiency will be improved, but fuel consumption is still relatively high at low speeds. Although CVT also has torque converters, it also has the problem of low transmission efficiency. However, since CVT is a continuously variable gear, in the process of adjusting the diameter of the front and rear driven wheels, it is similar to constantly shifting gears, which is equivalent to countless gears.

If the AT transmission has some excess power in 2nd gear, 3rd gear is still slightly underpowered, and it tends to drive in 2nd gear. At this time, excess power means increased fuel consumption, and the CVT has a gear equivalent to "and" to switch. The tuned CVT gearbox is always in the best "gear", so it plays a role in fuel saving.

In conclusion, the CVT gearbox is fuel-efficient because it allows for continuously variable shifting, always driving in the best gear. Since there are many gears corresponding to 8AT and 10AT, it will also save fuel. CVT is mainly fuel-efficient compared with 6AT and 4AT, and has no obvious fuel-saving advantage compared with 8AT and 10AT.

There are two main reasons for CVT's fuel savings:

The power is transmitted by the friction of the steel belt or steel chain, and there is no mechanical gear, so there is basically no limit to the power output of the engine.

For example, a 4AT gearbox matched with a 2-liter naturally aspirated engine, assuming that the car is at 45 kilometers per hour, the gearbox gear is 3 gears, and the engine speed is 1400 rpm, and the car is at 65 kilometers per hour, the gearbox is upgraded to 4 gears, and the engine speed is 1600 rpm, due to the gear limit, when the car is driving at 55 kilometers per hour, the engine torque output is insufficient to rise to 4th gear, therefore, at this time, it can only still drive in 3rd gear, and speed up by increasing the engine speed, As the engine speed increases, fuel consumption inevitably increases. This is where the gear limits the engine's revs at optimal power output.

2.For CVT transmissions, the power is uninterrupted when changing gears, and the engine power is always continuously output, which is also a reason for saving fuel consumption.

In order to reduce the restriction of the gearbox on the engine, people have increased the gear of the AT gearbox, from the initial 4AT to the current 9AT, 10AT, etc., increasing the gear to make the gear curve smoother as much as possible. However, the more gears there are, another problem is that in order to cushion the impact, the AT gearbox must disengage the locking of the torque converter when changing gears and use a liquid transmission. Excessive gear shifting will inevitably lead to an increase in the hydraulic transmission section, which is not good for fuel consumption.

At present, CVT gearboxes are more used in Japanese cars, and now domestic cars are also using CVT gearboxes, which is the biggest feature is that the cost of CVT gearboxes is low, which can reduce the cost of building cars. Regarding the comparison of the fuel economy of the two gearboxes, the CVT is definitely more fuel-efficient than the AT, we see some small displacement cars, most of them use the CVT gearbox, in addition to fuel economy, there is also the CVT gearbox can withstand the torque is limited, too much engine power will damage the CVT gearbox, or the city travel, the first choice of CVT gearbox car.

In addition, CVT technology is also being updated, from the traditional belt transmission, to the current steel belt transmission, the advantage of steel belt transmission is that it can improve the power transmission of automobiles, although the use of steel belts, the technology of car dealers and car dealers is still very different, and some CVT gearboxes are old problems. Therefore, when choosing a car with CVT gearbox, it is necessary to refer to the failure rate of the car, especially the failure rate of CVT gearbox.

AT gearboxWe can find that some off-road cars are equipped with more prices, and some high-end models also choose AT gearbox. However, the smoothness of the AT gearbox is not as good as the CVT gearbox, mainly because the CVT gearbox is continuously variable and more fuel-efficient, and the AT is a gear shift, in addition to the frustration, it is more fuel-efficient than the CVT.

The advantage of the CVT mentioned above is that it is fuel-efficient, and the CVT gearbox of the big car manufacturer is also more durable and has a relatively long life. At the same time, the shortcomings of CVT are also more obvious than the gear, slow acceleration, not suitable for violent driving, more fuel-efficient than the traditional AT gearbox, mainly manifested in the CVT variable wheel refers to the smoothness of the gearbox is better than AT, and at the same time, because the CVT uses steel belt or belt to transmit power, so that the gearbox is damaged when driving violently, and the power and torque bearing are not as high as AT, so it is recommended that the CVT gearbox is the first choice for urban travel, and the AT gearbox is preferred for overtaking and violent driving.

The two fuel-saving models of the variable speed Qinghuai tank are about the same, and the answers are kept above 85%. The CVT gearbox is a little higher on top of the oil. The advantage is that the performance is clear and good. The disadvantage is the high cost of repairs.

AT gearbox is also known as hydraulic automatic transmission, mega slip is composed of hydraulic torque, planetary gears and hydraulic control system, theoretically CVT gearbox is slightly lower than AT gearbox oil consumption,

Yes, only jujubes, which are more fuel-efficient. The gear ratio of the CVT gearbox Yunshan Oak is continuous, and the CVT gearbox is better matched with the engine, so that the engine always works in the most economical speed range.

Because this kind of gearbox is a continuously variable gearbox, this kind of gearbox has no so-called gear, and the process of changing speed and torque of this gearbox is continuous, so there is no pause.

If you understand how a CVT gearbox works, it's easy to see why it's so smooth.

The structure of the CVT gearbox is very simple, there are two cone pulleys and a steel chain inside this gearbox, and the steel sail limb chain can be moved on the cone pulley, so that the gearbox can change the speed and torque.

The general gearbox has different gear sets, and the gearbox has a larger gear ratio span than the CVT gearbox, so there is a pause after shifting.

Let me give you an example.

The general gearbox is like going up the stairs, the stairs are composed of steps one by one, and the height of each step of the gearbox with many gears is very small, so that the frustration and collapse of the car is even smaller.

The gearbox with fewer gears has a higher height per step, so that the shift pause is relatively large.

The CVT gearbox directly replaces the stairs with a ramp, and there are no steps on the ramp, so the smoothness of the CVT gearbox is very good.

Common automatic transmissions are AT transmission, dual-clutch transmission, CVT transmission.

The smoothness of shifting in the AT gearbox is also very good, and the smoothness of shifting in the dual-clutch gearbox is the worst, and the frustration of this gearbox is more noticeable when driving at low speeds.

The transmission efficiency of the AT transmission is higher, but in general, because the power system of the AT transmission will be interrupted, its own weight will be larger, which will increase the fuel consumption of the vehicle. Therefore, although the transmission efficiency of the CVT gearbox is not as good as the AT, it is still more fuel-efficient than the AT in the end. Transmission efficiency refers to the transmission efficiency in a fixed gear, but in real life, it is impossible for us to drive in one gear.

Although the AT is more efficient, the energy loss of the AT shift is higher than that of the CVT.

In addition to the differences caused by different gearbox hardware, the coordination of the gearbox and engine is another important factor affecting fuel consumption. In fact, the subject's question should be asked like this: suppose the same car is equipped with CVT gearbox and AT gearbox, except for the different speeds, the other hardware is exactly the same, and the same person uses the same driving habits to walk the same road.

Why is CVT more fuel-efficient than AT? At present, there are two types of automobile transmissions: CVT transmission and AT transmission.

Since the transmission efficiency of the AT is higher, it is not as fuel-efficient as the CVT. Why is this happening? Because the CVT does not have a physical gear, which is not the case with the AT gearbox, it will forcibly tilt towards one of the two adjacent gear ratios, which will affect the engine speed and thus the power output of the engine.

Think about this question with a science student. The impact of shift lossesWe know that AT gearboxes are geared. It's essentially a manual gearbox, but the shift operation is done through the transmission controller, and then the torque converter is used instead of the clutch, which can both transfer power and change the speed and torque.

The specific realization mode is to add a directional wheel (guide wheel) between the pump wheel and the turbine of the torque converter, and realize the speed difference between the pump wheel and the turbine by controlling the speed of the directional wheel, so as to control the torque and speed transmitted by the pump wheel to the turbine. It leads to more losses, so it will increase the fuel consumption of the engine. The Thinkt gearbox does not have a fixed gear and can change with the engine ratio.

Therefore, there will be no additional consumption on the engine, and it will be more fuel-efficient. In addition, the CVT's power system can remain unchanged when changing gears, while the AT's gearbox interrupts power when changing gears, so it needs to buffer the power again after each gear shift, which increases fuel consumption.