Automatic or manual gearbox – is one type of gearbox better than the other?
The daysof manual gearboxes in Europe may be numbered. On the old continent, we have always used cars with gearboxes. However, in recent years, the trend towards decarbonisation has brought us closer to the United States, where automatic transmissions have traditionally been sold.
The debate on manual versus automatic gearboxes has been going on for decades. In fact, the positions on this issue are often quite radical. A person who enjoys driving not only does not mind the clutch and lever movements, but also enjoys them. On the other hand, there is the driver who is used to an automatic gearbox. Usually, this profile never thinks of going back to the clutch.
But which is better and which is more reliable? Well, it all depends on what type of driver you are, what your driving habits are, how you use the car and, above all, what type of automatic gearbox we are talking about. It may seem silly, but there are several types and not all of them work equally well or are as reliable.
- What types of gearboxes are available in modern cars?
- Manual
- Automatic – torque converter
- Automatic – Dual Clutch Transmission (DCT)
- Automatic – Variable Valve Timing Transmission (CVT)
- Manual and automatic gearbox. Reliability
- Reliability of manual gearbox
- Reliability of the torque converter automatic gearbox
- Reliability of dual clutch automatic transmission
- Reliability of CVT automatic transmission
What types of gearboxes are available in modern cars?
As we have already mentioned, before we start comparing, we need to understand the difference between a manual gearbox and the different types of automatic gearboxes on the market. In this case, we have stuck to the three most common automatic technologies used today, as there are many more that are outdated and rarely used in modern cars.
Manual control
Until recently, it was common in Spain to have a car with a manual gearbox.
It could be said to be the most mechanically simple system. This system allows us drivers to operate the clutch to disconnect the gearbox from the engine and to change gear via the gear lever.
Most manual gearboxes usually have 5 or 6 gears and a reverse gear. Relatively modern gearboxes are usually synchronised, with a system that allows smooth and unmediated gear shifting. However, we have already explained how double-clutching is carried out and where it is useful in practice.
For an experienced driver, driving this type of car is no great mystery. With a manual gearbox, you can shift up or down at will. This is not the case with an automatic car, where you increase or decrease gears mainly on the basis of algorithms. However, this is both a strength and a weakness of this transmission. Unless we learn how to shift properly, we will not always get the results we want.
- If we take too long to change gears, we will waste a lot of fuel, which will lead to inefficient and noisy driving and more wear and tear on the engine.
- The opposite is also not optimal. Too much shortening and too long a gear can lead to vibrations and poor accelerator response.
- But the most frightening thing about manual driving is braking. While it is true that occasionally braking the car is not a drama, there are drivers who choose an automatic car simply because they are afraid of braking. And, as we say, with practice this can be overcome by muscle memory.
Automatic – torque converter
Torque converter gearboxes are generally quite reliable. Instead of a clutch, it uses a series of hydraulic components to transfer power from the engine to the gearbox.
This system is mainly characterised by its smooth and gradual gear shifting. No effort is required on the part of the driver, and the system itself wears significantly less than a manual gearbox. However, the gearbox itself will need a lot of maintenance work, which needs to be properly taken care of.
However, the system is not perfect. If we want to change gears quickly, a torque converter is not what we are looking for. It is an interesting gearbox, but it will leave you wanting to have a more powerful engine in a car when you need to drive a bit more sportily.
Automatic – Dual Clutch Transmission (DCT)
DCT gearboxes were first seen in high-end cars such as Porsche, but now they can even be fitted to the Volkswagen Polo.
You think a car with an automatic gearbox is a good car until you test drive a car with a good double clutch transmission. And this system has the best of both worlds. It’s efficient and performs much better than a torque converter gearbox. But it also goes one step further. They can also change gears faster and more accurately than a human manual.
DCT gearboxes have a rather ingenious mechanism. They are based on two parallel drive shafts, each with its own clutch. One is for even gears and the other for odd gears. When changing gears, one clutch opens and the other closes at the same time, resulting in extremely fast gear changes.
And that’s not all. If, for example, you use the paddle shifters to change gears in the car’s manual mode, the change is also much faster than with a traditional manual gearbox.
Now that we have said all the good things about this gearbox, it is obvious that there must be something wrong with it. And indeed there is. These gearboxes are quite expensive. Of course, they are not all the same. Each manufacturer has its own patents and some products are better than others. They also have maintenance requirements that, if ignored, can lead to failures that will be hard on your wallet.
Automatic – Variable Valve Timing Transmission (CVT)
Finally, there is a type of transmission that has become very fashionable in recent years. Stepless transmissions are most commonly used in hybrid cars because they are a very economical system.
Unlike traditional gearboxes, CVT systems do not use fixed gears. Instead, it works with a system of pulleys connected by a metal belt. The diameter of these pulleys is constantly changing, so that the gear ratio can be adjusted according to the speed of the vehicle and the load on the engine.
The advantage of the system is that the vehicle is almost always running at the optimum speed range. It is also the most responsive of all the systems to the pace of urban traffic.
However, the system also has disadvantages. Driving without gears sometimes seems unnatural. In addition, there are occasions when gear changes can become sluggish or clumsy.
Manual and automatic gearboxes. Reliability
Now that we have identified the main systems, we can compare them and talk about reliability.
Reliability of manual gearboxes
If you drive a car with a manual gearbox badly, you will damage the clutch and have to replace it. It won’t be cheap
As we mentioned a few lines ago, the manual gearbox is the simplest of all. From a mechanical point of view, it is the least scientific. And in engineering, fewer parts usually means greater simplicity, which means reliability and savings.
What we mean is that if you drive a car with a manual gearbox properly , transmission maintenance will be minimal. A clutch that fails every 150,000 km due to wear, a pump that eventually fails due to wear… simple and fairly predictable failures.
But a manual gearbox can also become the most expensive if it is not used properly. Rough driving, clutch abuse and other habits that can be acquired over time will wear the system out in record time.
In any case, if we shift gears well, if we use the clutch pedal only for shifting and if we carry out basic maintenance, it is difficult for it to fail. Every few kilometres we will have to replace the clutch assembly, but this will not be due to failure, but simply to wear and tear.
Reliability of the torque converter automatic gearbox
Torque converter gearboxes are generally quite reliable. There are some models that fail, but this system has proven itself over the years to be very good.
Since the torque converter is based on a hydraulic system, it wears less than other alternatives.
However, all that glitters is not gold. If you own a vehicle with such a gearbox, maintenance is essential. And not only that. They are more complex than manual gearboxes and problems are inevitable. If maintenance is ignored, problemscan arise due to the temperature of the hydraulic fluid, and that is where our nightmares begin. We are talking about gearboxes, which are expensive to repair because of their complexity, and very expensive when they need to be completely replaced.
Reliability of dual-clutch automatic gearboxes
DSG gearboxes have become a Volkswagen trademark.
Historically, DCT gearboxes have only been available in high-end cars. Today, this has changed significantly. Many major brands have already switched to this technology. After all, they are more fuel-efficient and also offer a sportier performance.
Let’s talk about the disadvantages. Dual clutch systems are the most complex, and they are also quite sensitive. These transmissions are particularly affected in urban driving, where they are subject to a lot of wear and tear when constantly changing gears.
The cheaper DCTs are more prone to clutch failures. On the other hand, vehicles using more advanced transmissions with oil-immersed clutches tend to crash due to mechatronics. In this case, it is important to follow the manufacturers’ recommendations exactly and never skip gearbox maintenance in order to maximise the service life of these gearboxes . Repairs are very expensive and sometimes replacing a gearbox can cost more than the residual value of the vehicle itself.
Reliability of CVT automatic transmissions
CVT transmissions are used by Toyota, Lexus, Honda, Subaru and many other cars. These brands often have a reputation for reliability, which shows that CVT transmissions are very reliable.
As there are fewer moving parts in a CVT transmission, there is also less wear and tear. In situations where dual-clutch transmissions fail, such as in heavy traffic, CVT transmissions perform very well.
But they are not perfect either. If the vehicle is used very intensively, if it is operated roughly, or if too much weight is loaded, the metal belt and pulleys are severely affected. Powerful engines and sporty driving are not kind to the system and changes in fluid temperatures can shorten the life of the whole assembly.
If the CVT gearbox needs to be repaired, the bill will not be cheap either. In any case, when integrated into a small car and used for its intended purpose, this system rarely fails if it is maintained in good condition and in accordance with the manufacturer’s instructions.
Conclusions
When buying a vehicle , you need to take into account all the parts that go into it. The gearbox is something that many drivers do not even consider when making comparisons. This is a mistake. The market is full of cars with faulty transmissions. Either because the manufacturer has not done its job properly or because the car buyer has chosen the wrong answer when configuring the car.
Is a manual gearbox the most reliable system? Yes, but because it is also the simplest. Failures in these systems are still jack, horse and king. So, is a manual gearbox the best? No, not at all.Because there are more factors to consider.
If you like to have full control of the vehicle, you should ideally buy a car with a manual or dual-clutch gearbox. The choice of one or the other depends on your taste as well as your wallet. One is very economical, the other the opposite.
Do you prefer simplicity? Or do you prefer to use only two pedals? Good. No one should judge you for that. It’s your car and your money. Just try as much as possible to buy a car with an automatic gearbox that fits your lifestyle.
For example, if you do a lot of city driving, a car with a CVT transmission is the best choice. On the other hand, if you do a lot of motorway driving, dual-clutch and torque converter transmissions are perfectly suitable.
Finally, if you’re looking for a vehicle with good performance and a good feel, forget both CVTs and torque converters. In this case, it is best to buy a vehicle with a DCT gearbox, such as the Volkswagen Group’s DSG.
