It is possible to learn how to properly shift gears on a manual transmission. It doesn't take much to do this. Firstly, an understanding of why a car needs a box with different gears at all. Secondly, you will have to memorize the algorithms of actions. Thirdly, to realize what tasks the ICIE can solve. Fourthly, to work out in practice some subtleties that allow you to achieve switching without jerks and other jambs.
Vehicle without gearbox
Imagine for a moment a car that does not have any kind of gearbox at all - manual transmission or automatic transmission. There is only the engine and the drive wheels, the torque between which is transmitted through the clutch mechanism. By the way, this is how the first cars were arranged. At that time, they didn’t even think about gearboxes, since there was no need for them.
It should be noted that it is impossible to simply connect the engine directly to the wheels. You need at least a downshift. This is one that reduces the speed of rotation of the drive shafts. The fact is that the engine, even at idle, spins quite quickly. If it is directly connected to the drive wheels, the car will not budge. The speed of rotation of the input shaft will be large, but the torque will be small.
Now let's try to ride on our imaginary car without a full-fledged transmission. It's not as easy as it seems. Firstly, you need to start not with starting the engine, but with depressing the clutch pedal. Remember that the drive wheels are directly connected to the motor. Not even a neutral gear. Pulled out the clutch. Next, we start the engine. Slowly release the clutch pedal and start moving.
We want to accelerate - we press the accelerator pedal. To slow down - we drop the "gas". Everything is extremely simple, but there is one caveat. It lies in the fact that our engine has a limited rev range. When its upper limit is reached (let's say 6000 rpm), a car without a gearbox will move at a speed of only some 40 km/h. Unfortunately, we won't be able to go any faster.
Vehicle with manual transmission
To solve the problem that arose in the previous example, we will add a manual transmission to the design of our car. The simplest. In fact, this mechanism will solve only one single task - to convert the speed of rotation of the motor shaft. Lower gears will lower it. The highest one connects the motor and wheels directly.
Let's drive our car now. Let's imagine that our manual transmission also has a neutral gear. This is one in which no torque is transmitted to the wheels from the engine at all. Thanks to this, we can now safely start the engine without depressing the clutch pedal. We start and move off in the same way as in a car without a manual transmission. Only now, after depressing the clutch, we need to turn on the lowest, that is, first gear.
Raising the engine speed, we accelerate. Having typed, as in the previous example, the speed of 40 km/h, we can now accelerate further. To do this, we need to switch to a higher gear, that is, to second gear, on the go. Depress the clutch, shift, release the clutch back, and continue to accelerate. It is necessary even faster - we turn on the third, fourth and so on. The last gear on the mechanics is usually direct. This means that the torque from the engine to the wheels is transmitted directly, that is, without reducing the speed of rotation.
Let's supplement our story with a couple of life situations that drivers of cars with manual transmission face on a daily basis. Let's say we have a hill ahead of us. We most likely will not be able to drive into it in the highest gear. And all because we do not have enough torque on the drive wheels. To add it there, we turn on a lower gear. Now the car will go slower, but it will have more so-called traction. Accordingly, we will be able to call on our hill.
Here is another situation where mechanics are useful. On our way there is a road sign that limits the speed of movement, or we need to quietly drive past the traffic police post. We can't just let off the gas in the highest gear. This will not be enough - the car will slow down a bit, and with further deceleration, the engine will start to stall (slower rotating wheels will slow it down, forcing it to work below idle speed). To solve this problem, we just need to turn on a lower gear, for example, third or even second.
The last illustrative situation that I would like to mention is overtaking other vehicles. The task is to drive into the oncoming lane to carry out this maneuver and stay there for as little time as possible. To solve it, we need a vigorous acceleration. Therefore, if we are driving in the highest gear, it makes sense to switch to a lower gear before overtaking. For example, from fifth to fourth. Now, using the engine speed reserve, we can transfer more powerful torque to the drive wheels, and accelerate for a short time. Problem solved.
Advantages and disadvantages of manual transmission
Read more about this in the article about which is better - automatic or mechanic. Here we will consider this issue very concisely.
- comparative simplicity of the device;
- lower cost of cars with manual transmission;
- wider choice of cars;
- cheaper to maintain than automatic transmission;
- smaller and lighter:
- with skillful use, it helps to save fuel;
- gives a special feeling of driving a car;
- a car on the mechanics is considered more passable.
- difficult to learn how to shift gears correctly;
- there are also problems with starting uphill;
- when driving in city mode, you often have to work with the box;
- driving in traffic jams is a little more tiring than driving an automatic;
- with inept use on mechanics, it is easier to reduce the life of the engine.
As you can see, the advantages are not so few. The main ones are probably a wider range of cars with manual transmission, as well as the fact that they are cheaper than analogues on the machine. As for the shortcomings, more than half of them leave with the acquisition of experience and relevant skills. If you carefully read further, then in five to seven minutes these shortcomings will potentially begin to melt before your eyes.
Engine RPM and Gear Shift
The tachometer on the dashboard, if any, is one of the most visual "helpers" of the correct gear shifting on the mechanics. The main thing is to know the basic principles, how to navigate it. To do this, we conditionally divide the tachometer scale of a car with a standard gasoline engine into the following zones:
- 0-850 rpm - in this range, the engine either does not work at all, or does it unsteadily, intermittently, choking and coughing.
- 850-950 rpm - the so-called idle speed, which is needed to warm up the engine, diagnose it, stand in a traffic jam or at an intersection, and so on.
- 950-2000 rpm - low revs, at which the torque is generated extremely low, and therefore you should not ride them.
- 2000-3500 rpm is the optimal range for riding, with the upper limit being the point of maximum possible torque.
- 3500- ∞ rpm - high speeds at which the torque no longer grows, but the fuel consumption is still the same.
It is worth clarifying that depending on the make and model of the car, the upper limit of the optimal range for driving is slightly different. For example, on domestic VAZ cars it is 3000 rpm, and on some foreign cars it reaches 4500 rpm. Diesels are more modest. For your car, this figure can be found in the technical specifications. In a paragraph that indicates at what speed a particular power unit develops maximum torque. Further in the examples, the figure 3000 rpm will appear, since it is relevant for most passenger cars with gasoline engines.
From the list considered, it follows that the correct gear shift will be one in which the engine speed will not go beyond the optimal range. That is, something like this. We turned on the first gear, started off and accelerated until the engine spins up to 3000 rpm. This is the time to shift to the next, that is, to the second gear. Then we accelerate in the same way.
To slow down, we act in exactly the opposite way. Let's say we are driving in fifth gear and the tachometer is 2800 rpm. We reset the "gas" until the arrow drops to 2000 rpm. This is the best time to shift into a lower gear, i.e., fourth. If we need to reset the speed to some minimum, then it is not necessary to turn on the fourth one. When the transmission slows down, it is quite possible, and even necessary, to jump, comparing the speed of movement with them.
Driving speed and gear shifting
We smoothly move on to the next "assistant" in the correct gear shifting on the mechanics - the speedometer. This device displays the current vehicle speed. Actually, it will have to be guided by when teaching those who simply do not have a tachometer on the panel. Looking ahead, we note that in the case of slowing down and “jumping” gears, it is the speedometer that is the best “assistant”.
By the way, you can focus not only on devices. As a matter of fact, they also go without them at all. Experienced drivers "feel" how to properly shift gears on the mechanics. The sound of the engine helps them in this, a personal feeling of the speed of movement, as well as how the car pulls - cheerfully or “choking”.
But back to the speed at which to shift gears on the mechanics. The first way is to use a universal cheat sheet. It is suitable for most cars with gasoline engines. Plus, or minus a few km/h. Previously, such cheat sheets were present in printed car manuals. If you have one, then this is the second way. More correct and accurate.
Actually, this scheme works on the same principle as in the case of turnover. Manufacturers of mass-produced cars specifically select gear ratios for manual transmissions so that they roughly correspond to both the optimal rev range and the usual speeds.
In addition, it is comfortable to ride in some standard situations. For example, it is more convenient to move around the city in third gear, choosing the speed that is most appropriate for the flow from the range of 40-60 km/h. Previously, it was also convenient within the boundaries of settlements, where the 60 km/h limit was in effect according to traffic rules. That is, he turned on the fourth gear, and rolled with minimal speed. Now the restriction has been tightened, and driving at the same fourth speed at a speed of 50 km/h is, as it were, wrong. There are not enough turnovers.
Shifting gears on the mechanics without jerking
The next important step in mastering the skill of shifting on a manual transmission is to eliminate jerks. Achieving smoothness is perhaps more difficult than learning all the other tricks, and therefore we will consider this issue in a little more detail. To do this, mentally sit behind the wheel of a car, and start moving. Everything is as usual, but now we will do it consciously. Understanding what is happening and how to avoid it.
So, the first task is to accelerate, and switch to the next gear without jerking. The algorithm is simple:
- Let's go.
- We spin the engine up to the 3000 rpm, mentioned above.
- Depress the clutch pedal.
- Release the gas at the same time
- We turn on the next transfer in a row.
- Release the clutch pedal.
- We increase the speed to the required level.
All these actions are performed in a second, but at the same time, our car could jerk more than once, or twice. A whole five times. Our task is to understand at what stages and why this happens, and how to eliminate jerks.
The first jerk may have occurred at the point where you started depressing the clutch pedal. That is, at the third step of the above algorithm of actions. This happens because you were in a hurry and started to press on the clutch pedal too early. The fact is that during acceleration, the engine does not quickly increase its power. You added "gas" and hold the pedal in one position, and the motor continues to spin up at this time, so to speak, "catching up" with your actions.
And now, if you do not wait until the engine “catches up” with the accelerator pedal you pressed, and squeeze the clutch, a jerk occurs. But not forward, but relatively speaking, back. This is due to the fact that the car was accelerating, and with your foot you abruptly took away from it what accelerated it. The acceleration changed the vector and the car began to slow down. You, and your passengers, feel the nod. A particularly good "indicator" is the passenger next to the swami - you can literally see how he nods his head during such actions.
To eliminate this type of jerk from your driving, do not rush to depress the clutch pedal while accelerating the car. Wait a second or fraction of it for the engine to "catch up" with your actions and move without acceleration. As a matter of fact, if you have not accelerated before, but were driving smoothly and decided to switch, there should not be a jerk at this stage.
The second jerk could happen a little later if you unsynchronously and too sharply released the “gas” pedal and squeezed the clutch. This must be done simultaneously and smoothly. Not so, of course, as when starting off. But not abruptly either. Remember that the engine reacts to the dropped “gas” faster than the car to the clutch being squeezed out. The latter is triggered when the pedal travels about a third of its travel.
The third jerk often occurs at the moment when the next gear is already engaged, but the clutch pedal was released too abruptly. This should also be done more or less smoothly. But not so, again, as when starting off. Here, too, one must understand and remember that the clutch starts to work somewhere in the middle of its stroke. That is, after the gear is engaged, the pedal can overcome the first part of the path quickly, then at the moment the box is connected to the engine smoothly, and the remaining stroke is again fast.
Fourth jerk is possible due to the fact that you spent too much time shifting gears and finding the optimal speed for releasing the clutch pedal. During this time, the engine speed dropped to idle, so when it is connected to the drive wheels, a nod occurs. The motor simply cannot instantly equalize the speed that the drive wheels “dictate” to it at this moment with the gearbox.
To eliminate this next nod, there are two ways. Firstly, you can practice, and perform all the manipulations with the pedals and lever faster. Secondly, if the first fails, the engine speed is maintained at 2000 rpm by the accelerator pedal. Or add them in a timely manner (at the moment the clutch mechanism is triggered), if the “gas” was completely released before that.
The fifth jerk no longer refers to acceleration, but to the reception of a downshift with a jump. It occurs in cases where the selected gear does not correspond to the desired speed and the optimal engine speed for it. That is, you need to either carefully select the gear, or adjust the engine speed so that when it is connected to the box and wheels, there is no sharp drop.
Here is an example algorithm for how to achieve this:
- We are driving in 5th gear at a speed of 90 km/h.
- You need to slow down to 50 km/h.
- For this speed, third gear will be optimal.
- But the speed should be somewhere around 2500 rpm.
- We throw "gas".
- Depress the clutch at the same time.
- We switch from fifth to third.
- We bring the speed to the specified.
- And only then we connect the engine with the box using the clutch.
- For other speeds, select the appropriate gears and revolutions.
Perhaps in the form of letters it all looks very complicated. Not without it. But when experience comes, you will understand that it is simple. All these algorithms and rules will be obtained by themselves, moreover, in much larger versions. After all, this is the beauty of mechanics - it allows you to control the machine as flexibly as possible, squeezing out of it exactly as much as this or that situation requires.
Economical mechanical driving
It is short here, since the principles of economical driving on mechanics are extremely simple:
- The lower the engine speed, the lower the fuel consumption.
- Beyond the point of maximum torque, fuel is burned extremely inefficiently.
- If the revolutions are less than necessary to overcome the load, an overrun begins.
In total, ideally, in order to drive the mechanics most economically, you need to adhere to all the guidelines described at the beginning of the article. Turnovers are in the optimal range. Speed - corresponds to the included gear. In addition, if the situation allows, you can try to drive at lower speeds than 2000 rpm. This includes movement from a small hill, behind a strong wind, and so on. That is, when the car goes with minimal resistance from external factors.
Gear shifting and engine life
It is not worth it to get too carried away driving at low speeds. Although this has not been proven by anyone in practice, there is a theory about the so-called oil starvation. It consists in the following. In order for the lubrication system to fully work, there must be sufficient pressure inside it. And it is created by a pump, the performance of which directly depends on the engine speed. Accordingly, if they are low, the lubricant gets worse to the upper parts, as a result of which their wear is allegedly accelerated.
Others say it's all nonsense. Especially if the car is more or less modern. Proponents of this anti-theory argue that oil pumps are now being made very efficient, and they are able to create the desired pressure in the system already at 1500 rpm. Is this so - you need to ask the manufacturers of specific machines and motors.
Even supporters of the theory of increased wear often talk about the crankshaft, which at low speed does not create high-quality oil mist. The latter lubricates the parts of the crank mechanism and the cylinder walls. Again, is it so - it is impossible to see with your own eyes. Moreover, no one has clearly proven that everything described reduces the life of the motor.
“Incorrect” gear shifting by situations
In conclusion, it remains only to list the situations when it is necessary to shift gears on the mechanics, so to speak, “wrongly”. That is, regardless of engine speed, speed and other factors. You also need to know about this when owning a car with a manual transmission. Moreover, all these techniques need to be learned. Preferably before they are needed in the real world.
In general, these are non-standard situations that require the same methods of handling manual transmission:
- When driving through railway crossings, it is strictly forbidden to switch.
- A maneuver called overtaking must be calculated so that it is entirely carried out in the same gear.
- If there is a steep climb ahead, it is better to engage a lower gear in advance.
- It is also better to avoid switching before going down the hill.
- In ice it is safer to drive at lower speeds than expected, especially if you (or rather, the car) have rear-wheel drive.
- Turns, including long ones, are also highly recommended to take place in one gear.
- In ice conditions, we perceive the previous paragraph not as a recommendation, but as a rule.
- If you need to accelerate sharply and vigorously, it can be useful to switch to a lower gear, giving as much revs as the engine can give.
As you can see, in all these situations, there is no time to think about optimal speed, efficiency or engine life. That is why there are exceptions to the rules.
VIDEO: how and when to change gears
Now you know more about how to ride a mechanic. Although this is only a theory, nevertheless, it cannot be dispensed with. It remains only to practice, gain experience, learn to understand and feel the car, pump, so to speak, your level of driving. In fairness, we note that the above is far from everything you need to know about a mechanical transmission and its operation. Having mastered the described techniques, do not stop there. For there is no limit to perfection.