What rpm to drive, economy mode, low rpm, high rpm and how does this driving mode affect the car engine. What rpm to drive, economy mode, low rpm, high rpm and how does this driving mode affect the car engine

Many drivers (both beginners and experienced) often ask the question - what rpm is better to drive? Since the opinions of supporters of different driving styles differ significantly, in this article we will try to determine the only correct driving style that will help keep the engine for many kilometers until it is overhauled.

The first and main rule of driving in economy mode is to avoid dynamic acceleration and high speeds... In order not to burn fuel in vain, you should get used to a measured set of speed and "stimulate" the engine to work more in economy mode - at 2000-3000 rpm, when specific consumption the fuel consumption of most motors is minimal.

When accelerating, press the gas pedal as gently as possible. Any sharp swirling is not recommended - it is necessary to maintain a constant speed on the track. To engage the next gear, you do not need to spin the engine up to high revs - it is enough to switch at optimal (medium) revs. To reduce fuel consumption when decelerating, it is necessary to move in higher gears as long as possible.

It is better to navigate in the city avoiding vehicle stops. Starting off is the most uneconomical mode of movement, which should be avoided whenever possible.

Remember that the engine in warm-up mode consumes twice as much fuel as at operating temperature. Therefore, it is better to reduce the warm-up time of the power unit by standing car - it is advisable to start moving as soon as possible after starting.

However, it is necessary to apply the rules of economical driving wisely in order to avoid interfering with other road users.

Low engine rpm, negative driving torques at low rpm

There are two types of motors internal combustion:

Low-speed (for example, Moskvich 2141).
High-speed (from classics to Grants or Priors).

The first version of the engine is low-speed. It is not designed to spin the motor to achieve high speed, but for traction. Slow-speed internal combustion engines are similar to diesel types. The maximum torque (for the petrol type) is reached at low revs (about 2500 rpm).

For high-revving powertrains, peak torque is reached in the 3500-4500 rpm range. In this way, vehicle pulls better at high speeds.

When operating a high-speed motor at low speeds, the following occurs:

Oil starvation. At low speeds, the oil pump delivers oil at a low level when the bearings (crankshaft liners) are under heavy load. As a result of low oil pressure, the rubbing elements of the motor are poorly lubricated, as a result of which they begin to rub against each other, which leads to overheating and seizure of key engine mechanisms.
Carbon deposits form in the combustion chamber. Fuel does not burn completely, nozzles and spark plugs are clogged.
The camshaft is under load. The piston fingers begin to knock.
Detonation occurs, that is, the fuel explodes earlier than necessary (self-ignition), an increase in the load on piston group... The motor heats up and twitches more.
There is an increase in the load on the transmission. The gearbox is poorly lubricated and is forced to work under load, as a result of driving "vnatyag".
Poor throttle response on the road. When a dangerous situation arises, it is unrealistic to quickly accelerate.
Fuel consumption increases. To accelerate at low speeds, it is necessary to press the gas pedal much harder than when the engine would have been spun, therefore, an additional enrichment of the mixture occurs and high consumption fuel.

High engine speed, negative moments when driving at speeds above 4500 rpm

Many drivers, having learned about the disadvantages of driving at low speeds, are of the opinion that it is necessary to drive only at high speeds, that is, with the number of engine revolutions over 4500 per minute. This mode of operation of the power unit also has several disadvantages:

With constant movement at high speeds, the lubrication systems of the engine elements and its cooling are forced to work without reserve, as a result of which even a faulty thermostat or a radiator clogged from the outside can cause off-scale engine temperatures.
When driving at high speeds, the lubrication channels are clogged quite quickly, which, together with the use poor quality oil (and few people use high-quality lubricant), leads to the "sticking" of the liners, which in the future can lead to failure of the camshaft.

What rpm to drive, or optimal engine rpm

Experts in automotive industry agree that the optimal mode for the operation of any "engine" is the speed mode 0.35-0.75 from maximum number revolutions for this motor - it is when driving in this mode that the motor will give out the best indicators of wear resistance. If the car has just been purchased, that is, it is being run-in, you do not need to accelerate the engine by more than 0.65 from maximum speed power unit.

Driving performance at medium speed (2800-4500 rpm)

The main driving factors at medium speeds:

The fuel burns out completely; carbon deposits do not form in the cylinders.
The accelerator pedal is pressed less, therefore fuel consumption is also lower.
You can pick up speed easily.
The motor runs without loads.

To keep the engine in "shape", spinning it up to maximum speed is sometimes useful for self-cleaning from carbon deposits in the cylinders.

Pro tips on what to look for when driving and what it means to hear the engine

Riding at medium revs is most acceptable. In general, you need to hear the engine and feel the thrust. If the gas pedal is released and you go down the hill, then the rpm 1500-2000 is not harmful, since the engine does not work "vnatyag".

Is the roar under the hood scary?
On the tachometer, the red zone starts at X rpm. What turns can be considered (of course, we are talking about intervals):
normal

optimal (in terms of consumption, resource, etc.)

permissible (one-time, at short intervals, at large)

extreme

unacceptable

Without going into details, there are 2 main sources of engine speed-related damage:
Problems related to the tensile strength of parts;

Oil pressure versus speed.

With regard to strength, for a properly assembled engine, it can withstand the maximum speed prescribed by the manufacturer (red zone of the tachometer) without harm + another 10% - easily. The danger of "twisting" the engine, as a rule, exists on an unloaded engine (well, for example, if the accelerator pedal "fuses" in neutral). When driving with a gear engaged, during "twisting", "special effects" arise, such as: separation of valves from camshaft cams, "suspended" state piston rings, violations in the interrupter are mainly associated with the inertia of non-rotationally moving parts. In addition, when "twisting", the engine power drops sharply. All this taken together sharply reduces the intensity of acceleration and makes you understand that there is simply no point in "turning" higher, and will prompt you to shift the gear to an upward one. In this case, the engine will not receive any significant harm.
In general, it would be more correct to talk about engine hours, and even more correct - about engine hours multiplied by the average load (with regard to the influence of the speed on the durability and mechanical strength of parts).
Now about the oil pressure. Here the source of "harm" is low engine speed, or rather the speed at which it is still closed pressure reducing valve oil pump (this valve opens when the design oil pressure is reached - about 3.5 kg) Of course, the oil pressure depends, in addition to the speed, also on the viscosity of the oil, its temperature, etc., we will omit these parameters for now. The first main point is that when the calculated oil pressure is reached, the "harm" to the engine from the speed is minimal. The second point is that the maximum damage to the engine is caused at idle speed, as well as when it is started and stopped.
This is something that car manufacturers have to put up with, as the complete solution is autonomous electric drivewhen the oil pressure reaches the design pressure before the engine is started. However, this is quite expensive.
A partial solution is to increase the capacity of the oil pump (usually by increasing the height of the gears).
However, I was distracted.
The oil pressure depends, in addition to the number of revolutions, also on the total cross-sectional area through which the oil flows out (in the main and connecting rod bearings, basically). These sections increase over time, and the "harmless speed" shifts "up".
Key findings:
"Twisting" is not harmful, "twisting" is not worth it.

It is always better to drive at a slightly higher RPM than most drivers are expected to do.

If the red oil pressure lamp does not go out immediately when the engine is started, change the oil filter.

AUTO LOVER CLUB

/ "KETTLE" NOTE

TO SPIN OR NOT TO SPIN?

ENGINE LIFE DEPENDS NOT ONLY ON THE MAKE OF THE CAR, BUT ON THE DRIVING PRACTICES

TEXT / ANATOLY SUKHOV

WITH "CLINYSHK"

Instructors who teach how to drive "vnatyag" at minimum speed, they say, will wear out the engine less. Some of them even bend the pedal or put a wooden stop under it - then, with all the desire, you cannot fully open the gas. And then another driver goes - with a "wedge", frightened, as soon as the tachometer needle crosses the 2000 mark. This style is justified by fuel economy, by taking care of the engine.

When it comes to fuel economy, this is only partially true. At low revs, the engine does not pull, therefore, when overtaking or on a more or less noticeable rise, an adherent of this driving style is forced to "trample" the gas pedal, further enriching the mixture and burning the saved fuel.

So, maybe we win in the resource? At first glance, the answer is obvious: less engine speed means lower relative speeds of movement of parts, and accordingly wear decreases. But it's not that simple. The most critical plain bearings ( camshaft, main and connecting rod journals crankshaft) are designed for hydrodynamic lubrication. Pressurized oil is fed into the gap between the shaft and the liner and absorbs the arising loads, preventing direct contact of parts - they simply "float" on the so-called oil wedge. The friction coefficient for hydrodynamic lubrication is extremely small - only 0.002–0.01 (for lubricated surfaces with boundary friction it is tens of times higher), therefore, in this mode, the liners can withstand hundreds of thousands of kilometers. But the oil pressure depends on the engine speed: the oil pump is driven by the crankshaft. If the load on the engine is high, and the rpm is low, the oil wedge can be pushed to the metal, and the liner will begin to break, and the wear progresses rapidly as the gaps grow: it is more and more difficult to create a "wedge", there is not enough oil supply.

In addition, when driving at low revs, shock loads occur in the engine and transmission. The inertia of the rotating parts is no longer sufficient to smooth out the resulting vibrations. The same happens when starting off. Let's remember a driving school: as soon as the clutch is suddenly released at low throttle, the car starts jumping. Sometimes this ends in a breakdown of the clutch: the elastic plates of the driven disc to the casing cannot withstand, they burst, springs jump out of the windows. It is better to lose a little on wear, but avoid early breakdown.

So, the more we require from the motor (sharp acceleration, rise, loaded car), the higher the rpm should be. Conversely, when driving quietly, when the engine is lightly loaded, it makes no sense to drive the tachometer needle to the end of the scale.

GOLDEN MEAN

Accelerated wear of liners is not the only evil from being carried away with low revs. During short trips in such modes, low-temperature deposits accumulate in the engine, primarily in the lubrication system. It is worth "grabbing" on the highway - and hot oil under pressure will thoroughly flush the system, at the same time, excess carbon deposits in the combustion chambers and piston grooves will burn out. Sometimes this is how it is possible to restore the compression in the cylinders that has decreased due to the occurrence of the rings.

Disassembling the "Zhiguli" engine, many paid attention to the erased grooves on the end of the valves - traces of levers. These marks mean: the valves did not rotate, but worked in one position all the time. Meanwhile, the rotation of the valve prolongs its service life, only it is possible at revolutions over 4000–4500 rpm. Few bring the motor to these modes, so a notch appears on the valves. And then she herself will interfere with their rotation.

But long work near the red zone is also not good for the engine. Cooling and lubrication systems are working at their limit, without reserve. The slightest defect of the first - a radiator clogged with fluff from the front or a sealant from the inside, a faulty thermostat - and the arrow of the temperature gauge will be in the red zone. Bad oil or clogged lubrication channels can cause scoring on parts or even "sticking" of liners or pistons, camshaft breakage. Therefore, "racers" should not lose sight of the pressure gauge and temperature indicator. A serviceable engine, fueled good oil, transfers maximum speed without problems. Of course, in this mode, its resource decreases, but by no means catastrophically - if only the spare parts were not "left"!

Between these two extremes lies golden mean... Depending on the specific conditions, the optimal mode is 1 / 3–3 / 4 revolutions maximum power... In the run-in mode, too low revs, and the upper limit should be lowered to 2/3 "maximum speed". But main principle remains unshakable - the higher the load, the higher the speed should be.

COLD START

Starting in cold weather is not good for the motor. Gasoline condensed on the cold cylinder walls does not burn, but dilutes and washes off the oil film from them. Therefore, high revolutions are harmful to an unheated engine, and at low speed old carburetor engines do not pull. Injection motors allow you to drive right away, but it is better to wait a minute until the oil scatters at least a little through the system and goes to all nodes.

Oil starvation can occur immediately after start-up, if the oil does not have time to return to the sump and the pump takes a sip of air. Therefore, if the low oil pressure light comes on, immediately turn off the engine for 30–40 seconds - let it drain. The reason can be both too thick oil, and its insufficient level or a clogged oil receiver (ZR, 2002, No. 4, p. 188).

HEATSTROKE

This danger lies in wait for the driver, who is always in a hurry: having won some seconds in a crazy race, he flies to the sidewalk, turns off the ignition and ... at the same moment the engine temperature begins to rise. A second ago, the heat balance of the engine running at high speeds was maintained by the intensive circulation of the coolant and the blowing of the radiator. But then the pump that pumped it stopped, and the pistons, valves, cylinder head are still very hot. Sometimes the liquid even has time to boil, and the steam removes heat hundreds of times worse. After several such overheating, the cylinder head may deform, burn out its gasket - repairs are not cheap.

There is only one way out - after active driving, let the engine cool down at idle speed for at least 15–20 seconds. This is especially important on turbocharged engines. Replacing a failed turbine will cost more than the time saved.

THE MORE WE DEMAND FROM THE MOTOR (SHARP ACCELERATION, LIFT, LOADED VEHICLE), THE MORE REQUIREMENTS SHOULD BE

OPTIMUM MODE - 1/3 - 3/4 ROTS OF MAXIMUM POWER

LARGE SPEEDS TO A UNHEATED ENGINE HARMFUL

AFTER ACTIVE DRIVING, LET THE MOTOR COOL ON IDLE

Almost every driver is well aware that the resource of the engine and other vehicle components directly depends on the individual driving style. For this reason, many car owners, especially beginners, often think about which revs are best to drive. Next, we will consider what engine speed you need to keep taking into account different road conditions during the operation of the vehicle.

Read in this article

Engine resource and revolutions while driving

Let's start with the fact that competent operation and constant maintenance of optimal engine speed allows you to increase the engine life. In other words, there are modes of operation when the motor wears out the least. As already mentioned, the service life depends on the driving style, that is, the driver himself can conditionally "regulate" this parameter... Note that this topic is the subject of discussion and controversy. More specifically, drivers are divided into three main groups:

the first are those who operate the engine at low speeds, constantly moving "vnatyag".
the second should include those drivers who only periodically spin their engine up to above average rpm;
the third group is considered to be car owners who constantly support power unit in the mode above medium and high engine speed, often driving the tachometer needle into the red zone.

Let's understand in more detail. Let's start with a low-end ride. This mode means that the driver does not raise the revs above 2.5 thousand rpm. on gasoline engines and holds about 1100-1200 rpm. on diesel. This driving style has been imposed on many since the days of driving schools. Instructors authoritatively argue that it is necessary to drive at the lowest rpm, since in this mode the greatest fuel economy is achieved, the engine is least loaded, etc.

Note that during driving courses, it is advised not to turn the unit, since one of the main tasks is maximum safety. It is quite logical that low revs in this case are inextricably linked with driving at low speeds. There is logic in this, since a slow and measured movement allows you to quickly learn how to drive without jerks when changing gears on cars with manual transmissions, teaches a novice driver to move in a calm and smooth mode, provides more confident control over the car, etc.

Obviously, after receiving driving license this driving style is further actively practiced in your own car, growing into a habit. Drivers of this type start to get nervous when the sound of a spinning engine starts to be heard in the cabin. It seems to them that an increase in noise means a significant increase in the load on the internal combustion engine.

As for the engine itself and its resource, too "sparing" operation does not add to its service life. Moreover, everything happens exactly the opposite. Imagine a situation when a car moves at a speed of 60 km / h in 4th gear on smooth asphalt, rpm, for example, at around 2 thousand. In this mode, the engine is almost inaudible even at budget cars, fuel is consumed minimally. At the same time, there are two main disadvantages in such a ride:

there is almost no opportunity to accelerate dramatically without switching to downshift, especially on "".
after changing the topography of the road, for example, on inclines, the driver does not downshift. Instead of shifting, he simply pushes harder on the gas pedal.

In the first case, the motor is often outside the "shelf", which does not allow the car to be quickly accelerated if necessary. As a result, this driving style affects overall driving safety. The second point directly affects the engine. First of all, driving at low revs under load with a strongly pressed gas pedal leads to detonation of the engine. The indicated detonation literally breaks the power unit from the inside.

In terms of consumption, the savings are virtually nonexistent, as pressing the accelerator pedal harder in overdrive under load causes the air / fuel mixture to richer. As a result, fuel consumption increases.

Also driving "vnatyag" increases engine wear even in the absence of detonation. The fact is that at low speeds the loaded rubbing parts of the motor are not sufficiently lubricated. The reason is the dependence of the performance of the oil pump and the pressure it creates engine oil in from all the same engine speed. In other words, sleeve bearings are designed to operate under hydrodynamic lubrication. This mode assumes the supply of oil under pressure to the gaps between the liners and the shaft. This creates the desired oil film, which prevents wear of the mating elements. The efficiency of hydrodynamic lubrication is directly dependent on engine speed, that is, what more revolutions, the higher the oil pressure. It turns out that with a high load on the engine, given the low speed, there is a great risk heavy wear and breakage of the liners.

Another argument against driving at low revs is the reinforced engine. In simple words, as the speed rises, the load on the internal combustion engine increases and the temperature in the cylinders rises significantly. As a result, part of the carbon deposit simply burns out, which does not happen with constant operation at the bottom.

High engine speed

Well, you say, the answer is obvious. The engine needs to be spinned harder, since the car will confidently respond to the gas pedal, it is easy to overtake, the engine will be cleaned, fuel consumption will not increase so much, etc. This is true, but only in part. The fact is that constant driving at high revs also has its drawbacks.

High turnovers can be considered those that exceed the approximate figure of about 70% of the total number of available for gasoline engine... The situation is slightly different, since units of this type are initially less revolving, but have a higher torque. It turns out that high revs for engines of this type can be considered those that are behind the "shelf" of the diesel engine torque.

Now about the engine resource for this driving style. Strong cranking of the engine means that the load on all its parts and the lubrication system increases significantly. The temperature indicator also increases, additionally loading. This results in increased engine wear and increased risk of engine overheating.

It should also be borne in mind that at high speed modes, the requirements for the quality of engine oil increase. Lubricant should provide reliable protection, that is, correspond to the declared characteristics in terms of viscosity, oil film stability, etc.

Ignoring this statement leads to the fact that the channels of the lubrication system with constant driving at high speeds can clog. This happens especially often when using cheap semi-synthetics or mineral oil... The fact is that many drivers change oil not earlier, but strictly according to the regulations or even later than this period. The result is the destruction of the liners, disrupting the operation of the crankshaft, and other loaded elements.

What rpm are considered optimal for the motor

To preserve the engine's resource, it is best to drive at such speeds, which can be conventionally considered average and slightly above average. For example, if the "green" zone on the tachometer assumes 6 thousand rpm, then it is most rational to keep from 2.5 to 4.5 thousand rpm.

In the case of atmospheric internal combustion engines, designers try to fit the torque shelf precisely in this range. Modern turbocharged units provide confident traction at lower engine speeds (the torque shelf is wider), but it is still better to spin the engine a little.

Experts say that the optimal operating modes for most motors is from 30 to 70% of maximum number revolutions while driving. Under these conditions, minimal damage is done to the powertrain.

Finally, we add that it is periodically desirable to spin up a well-heated and serviceable motor with quality oil 80-90% when driving along flat road... In this mode, it will be enough to drive 10-15 km. Note that this action does not need to be repeated often.

Experienced motorists recommend turning the engine almost to the maximum once every 4-5 thousand kilometers traveled. This is necessary for various reasons, for example, so that the cylinder walls wear out more evenly, since with constant driving only at medium speeds, a so-called step can form.

What does driving at low revs lead to?

Why all these numbers. The fact is that a high-speed type of engine, when operating at low speeds, experiences:

1. Oil starvation. Oil pump poorly delivers oil at low speeds, and at this time, bearings (crankshaft liners) are operating under heavy load. Due to low oil pressure, it poorly lubricates the rubbing parts of the engine and over time begins to rub “metal on metal”, which can lead to overheating and jamming of the main mechanisms of the power unit.

2. Carbon deposits form in the combustion chamber... Gasoline does not burn completely, candles and nozzles are clogged.

3. The camshaft is under load... Piston fingers begin to knock.

4. Detonation occurs, i.e. gasoline explodes earlier than necessary (self-ignition), a large load on the piston group. The engine twitches, heats up more.

... The gearbox is poorly lubricated and works under load due to tight driving.

6.. At low revs, to accelerate, the “gas” pedal is pressed more than if the engine was spun, therefore, additional enrichment of the mixture - hence the higher consumption.

7. Low throttle response on the road... In the event of a dangerous situation, it is impossible to accelerate quickly.

I probably scared you, now, the impression is that you need to drive only high revolutions. No, on high, also the load on all nodes of the car (,). The most acceptable ride on average revs... In general, you need to listen to the engine, feel the thrust. If you go down the hill ("gas" is released), then the revolutions 1500-2000 rpm not harmful, because the power unit does not work "vnatyag".

Main driving factors at medium revs (average revs in the range (2800-4500rpm))

The engine runs without loads;
Can pick up speed easily;
The accelerator pedal is pressed less, therefore, less consumption fuel;
The fuel burns out completely, no carbon deposits form in the cylinders;

In order for the engine to be in "shape", it is sometimes useful to spin it up to maximum speed, so that it self-cleans from carbon deposits in the cylinders, so to speak, "other".

Many people say: “here on idling the engine is normally lubricated, so you can ride them or just above XX ”.

Do not forget that at XX the engine runs without loads. In many books for car operation it is written that it is undesirable for the engine to work, more 15-20 minutes on XX.

Ride carefully, do not force the engine, and then it will serve you for many years.

That's all, see you soon.