Start stop timings for rectification. Why is it better to avoid using the Start-Stop system? And yet, is everything really as rosy as automakers are trying to present it to us? Are there really no flaws?
Many of you have heard of a system called Start-stop and, of course, everyone at least once wondered what kind of system this is and what role it plays in my (or someone else’s) car. Today I want to answer all your questions and tell you what the Start-stop system is, its main functions, and why it is so beneficial for you, your car and the environment.
So, let's take it in order...
The Start-Stop system was invented to:
- Reduce the amount of harmful CO released into the atmosphere.
- and, of course, money.
- Reduce the amount of noise emitted by the car by reducing the operating time of the internal combustion engine at idle speed.
In the era of environmental disasters and global warming, ecologists and statisticians began to pay attention to the little things that are actually quite large sources of air pollution. So, once a study was carried out as a result of which it turned out that about 30% of the total operating time of the vehicle it operates at idle speed. I don’t think it’s worth explaining where this 30% comes from; every motorist knows how much every day he has to sit idle with the engine running at traffic lights, in traffic jams during rush hour, etc.
Therefore the appearance Start-stop systems is a logical solution to the problem described above. More recently, Start-stop was installed exclusively on hybrid models, but as practice has shown, cars with classic engines running on heavy fuel or traditional gasoline need it no less. Experts predict that next 2015, about 50% of all cars produced in the world will be equipped with a start-stop system.
We talked about the history and numbers, now let's figure it out, what is a start-stop system and how it works.
And the principle of operation of the Start-stop system is ridiculously simple and banal - you drive, the engine is running, it stops, the engine stalls. In this case, starting the engine after stopping it, for example, at a traffic light, occurs automatically when you release the brake pedal in , or when you press the clutch pedal in .
What does the start-stop system consist of? The system includes:
- Special control system.
- A device that provides timely multiple starts.
There are several principles for implementing the engine stop and start function, among them:
- Starting with a boosted .
- Using fuel injection into the cylinders and subsequent ignition of the mixture.
- By means of a reversible (starter-generator).
The simplest and at the same time most reliable from a constructive point of view is considered to be the system Stop&Start from the world famous company Bosch. It was the development of this company that became the prototype for all systems of this class, in addition, the name of the system “stuck” to all analogues produced by other companies. This story is reminiscent of the story with Webasto (the name of the company that invented the first engine preheating; as a result, now whoever produces such a mechanism is popularly called Webasto). The Bosch start-stop system is used to equip cars from the most famous companies in the world: Audi, BMW and others. According to research data, fuel consumption after using this installation has significantly decreased, and the percentage of harmful CO emissions was less than 8%.
This system is based on a special starter, which is designed for a huge number of engine starts and a much longer service life compared to conventional starters. The starter uses an almost silent drive mechanism, which guarantees instant quiet starting of the engine.
The Start-stop system is capable of:
- Start the engine.
- Stop him.
- And also monitor the charge of the battery.
The start-stop system is based on:
- Control unit.
- Input sensors.
- Executive devices.
By input sensors we mean: clutch pedal position sensor (or brake pedal in the case of an automatic transmission), crankshaft speed sensor, battery sensor, as well as several other less important sensors of the internal combustion engine control system.
The system does not have a separate electronic unit; instead, it uses an ECU (electronic engine control unit), which contains the appropriate software.
Actuating devices include:
- Starter.
- injection systems.
- ignition systems.
How does the start-stop system work?
How the Start&Stop system works built in such a way that if the car comes to a complete stop at a traffic light or in a traffic jam, the “smart” system, guided by certain algorithms and data received from the crankshaft rotation speed sensor, stops the engine. At this time, the power supply to electrical consumers (radio, air conditioning, etc...) is switched to the battery. When the clutch pedal is depressed (or the brake pedal is released in the case of an automatic transmission), the system automatically activates the starter, which instantly starts the engine. The number of cycles is not limited and can be repeated indefinitely.
If , the corresponding sensor will notify the system, which will shut down the system. The start-stop system will be switched back on after the battery charging sensor reports that there is enough power in the battery for full operation of the system. Besides. the driver can manual mode to forcefully disable this system; for this purpose, the manufacturer provides a special button located on the instrument panel.
Kia Motors has its own Start-Stop system with a similar design, it is called - ISG (Idle Stop&Go). The main difference between this system is the ability to control a car generator in a special way. The ISG system is capable of turning off the generator during peak engine loads, this is done in order to relieve the load and thereby save fuel consumption. Conversely, when the driver presses the brake pedal and the engine does not need power, the ISG turns on the generator and recharges the battery. If the battery charge drops below 75%, the system shuts down.
Another equally successful system, STARS (Starter Alternator Reversible System) from Valeo, uses a reversible generator to save fuel. Cars from companies such as Mercedes and Citroen are equipped with this system, thanks to which car owners can achieve more than 10% fuel savings.
What is a reversible generator? Roughly speaking, this is an electric machine. alternating current, capable of alternating (changing) its work, performing, depending on the need, either the generator function or the starter function. The operation of this starter-generator is designed in such a way that, using a special drive belt and a reversible tensioner, it can transmit force in two different directions. The reversible generator operates quietly and has a much shorter starting time - 0.4 seconds, for comparison with a simple starter this time is 0.8 seconds.
Unlike the "Bosch" control system STARS is carried out by a separate computer that interacts with the electronic control unit of the internal combustion engine. All the rest - input sensors and other parts are almost identical to the system Start-stop from Bosch.
A new word among this kind of systems can be considered a relatively young system that uses regenerative braking, thereby forming additional source energy, reducing fuel consumption. The battery is charged while the car is braking.
SISS (Smart Idle Stop System)- a personal development of Mazda, which successfully competes with other start-stop systems. Here, the engine is started by injecting fuel into the cylinders and then igniting it. This installation is used mainly for gasoline units that implement the function of direct fuel injection.
In order to ensure optimal performance The SISS system stops the pistons in the engine cylinders in a certain position, which is most optimal for the subsequent start of the engine. When starting, a certain amount of fuel is supplied to the cylinders, then it ignites and the engine starts again. To help the engine start, the starter is turned on for a short time. This technology allows you to save about 9% of fuel, the disadvantage is that the system works exclusively with automatic transmissions.
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If you bought a new car 2.3-5 years ago and the car you purchased was average or high price category, most likely your machine has one of modern technologies, which mercilessly turns off the engine at every stop if the car freezes for more than 1-2 seconds. All this disgrace is called the Start-Stop system, and it was made for the sake of ecology and efficiency. Let's find out if the game is worth the candle.
The Start-Stop system is being promoted as a technology that is being touted as one of the most ingenious developments in the automotive industry, next in importance to the invention of windshield wipers or rear-view mirrors. Some automakers also call this feature "micro-hybrid technology." Why? We'll explain that soon.
In theory, the Start-Stop system has nothing but advantages. Do you want to minimize fuel consumption in the city and in traffic jams? New feature can provide it to you! Do you care about Mother Nature and don’t want to cause the disappearance of penguin colonies in Antarctica? Your desires here too can be satisfied by this simple system; statistically, the amount of emissions in the city for cars equipped with it actually decreases.
As is known from the official nomenclature, the Start-Stop system simply turns off the internal combustion engine (ICE), preventing it from idling during long (often not long) stops. When you need to get going, the device literally starts up with a wave of a magic wand, this will happen as soon as you take your foot off the brake pedal or press the clutch to engage first gear.
New vehicles equipped latest versions systems go from “off” to “on” almost imperceptibly, in the blink of an eye, literally.
Does the Start-Stop system harm the car's starter?
Since the system can fire multiple times in a short period of time, this can place significant stress on a standard starter, leading to premature failure. Therefore, cars that have similar system They use reinforced electric starters designed to work in difficult conditions with large repeated loads. Such reinforced elements can really extend life and survive stress.
Cars are also equipped with higher-quality batteries with larger capacity or additional batteries, which in some vehicles are charged through a regenerative braking system, thereby creating micro-hybrids. IN general scheme family of hybrid cars, micro-hybrids are located one step below the so-called “mild” hybrids (Mild Hybrid), and two steps behind conventional types of hybrid cars. *
*If you want to find out how many types of hybrids there are and how they differ from each other, go to our article: We will sort everything out for you there.
Some automakers resort to something called an integrated starter generator (ISG), while others use only a heavy-duty starter that does all the heavy lifting every day. Both versions of the Start-Stop system work in the same way and achieve the same effect, improving fuel economy by turning off the engine when stopping and starting it in a minimum amount of time when you need to start moving.
If we answer the previously posed question about the harmful effect of the system on the starter, then there are no official statistics on this matter yet. But from scraps of data collected from various sources, it is known that owners of cars equipped with the Start-Stop function have already experienced premature starter failure. Is this a direct influence of the system? Most likely yes, judging by the loads the starter experiences during such intensive work, but we will not officially blame the system for the failure of the starters.
All this is good and wonderful, especially since it is worth considering that this technology is not expensive and weighs much less compared to those weights that are found in conventional hybrid cars in the form of batteries and electric motors. Everything is very cool and thoughtful.
And yet, is everything really as rosy as automakers are trying to present it to us? Are there really no flaws?
1. Start-Stop system damages batteries
Modern cars have so many electronics and electrical consumers that they need large quantities electricity to continue to operate, especially when the main "volt distributor to the battery" is turned off. Headlights, climate control, audio system, even airbags will not work if there is no power. That's why in cars with Start-Stop system accumulator battery goes through much greater testing and is much more heavily loaded than in cars with a standard operating pattern.
2. Start-Stop will shorten the life of the machine, but it is beneficial for manufacturers
You'll probably say: “Hey, stop slandering! Automakers are not fools, they have thousands of engineers who have already thought for us about what is good for the car and what is not so good. Everything is calculated!” Of course, I’m also sure that they did it, they calculated everything... But in whose favor? Don't forget, the auto business is, first and foremost, a business. And their main goal is to sell cars as much as possible more cars. We live in the 21st century, no one anymore produces cars that can drive for decades and cover millions of kilometers during this time. Now everything is strictly limited, you want to drive, or pay exorbitant prices for spare parts.
3. Turbocharging is afraid of this system like fire.
Secondly, and this is a much more important factor, with most modern cars, this is also done mainly in the name of efficiency. You probably know to what high temperatures a turbine can reach under load. Older guys may remember that in every manual for a turbocharged car there was always a very important note, which urged drivers after an intense or high-speed trip NOT to immediately turn off the engine, but to idle it for a minute or two, allowing the turbine to cool. Even turbo timers were invented for these purposes, for those who value time and the good condition of the car is important.
Most new turbocharged cars use ball-bearing turbochargers, which are oil- and water-cooled, which should reduce the risk of overheating when the hot turbine suddenly turns off or coking of the oil passages. Please note that the risks only decrease, but do not go away.
So I'm not entirely sure what Start-Stop systems on powerful turbocharged cars like the BMW M-Series or Mercedes-AMG are. a good option to keep their engines running for many years.
And can you imagine what will happen to multi-turbine engines, which will very soon have two, three, and even turbochargers?
4. The Start-Stop system leads to rapid engine wear
And last, but certainly not least, even if you don't have a turbocharged engine under the hood, but your car cuts out the engine every time you stop, you will be faced with a durability problem, this time of the engine itself. Judge for yourself, a typical engine goes through approximately 50,000-100,000 start and stop cycles in its life. The motor that is supplied goes through a million/millions (?) of these cycles over the same period.
Taking care of environment- the motto of every automaker. This feeling appears after the release of another new product that allows you to reduce harmful emissions into the atmosphere and save fuel. Let's talk about electronic device for cars "Start-Stop".
What it is?
The main idea of Start-Stop is to turn off the engine in a situation where its operation is not required. For example, when sitting in traffic jams, or waiting for a green traffic light. When you approach a traffic light and stop the car, it will automatically turn off the engine. As soon as you take your foot off the brake pedal and press the gas, the car will start on its own.
It is clear that this will significantly increase the number of engine starts. This leads to the installation of a reinforced starter (it has six brushes instead of the usual four), as well as a high-capacity AGM battery with an increased charge-discharge cycle. The battery can quickly accept a charge, tolerates cyclic loads well, is not afraid of deep discharges and frost, and has a double resource. Some devices use a generator as a starter, which allows for silent starting.
The system is entirely based on electronic sensors and an engine control unit, with sensors located on all leading components of the car: wheels, battery, crankshaft, gearbox, generator.
When stopping the car, the speed sensor sends the ECU (to the “brains” of the car) a signal to turn off the engine. If the battery charge level allows this, the motor stops. Automatic start engine only occurs in neutral gear. The signal is to press the gas pedal or, with an automatic transmission, to release the brake pedal.
Operating principle and device
In the most common this moment The Bosch system uses a reinforced starter (4) and generator (8). The operation of the system is controlled by a standard engine control unit (1) with a modified software. It is he who turns off the engine based on signals from the wheel speed sensors (6). The go-ahead for starting is given by sensors on the clutch and brake pedals, not shown in the diagram.
Sensors for the position of the manual transmission lever (6) and the degree of battery charge (3) are needed to block the engine from stopping if there is little energy in the battery or any gear is engaged. And the crankshaft position sensor (7) is used to accurately stop the pistons in a position optimal for subsequent start-up. A stabilizer that compensates for the voltage drop (2) during engine starting is necessary for the normal operation of on-board consumers.
Does it save fuel?
The operating principle is not very complicated. A special feature of the Start-Stop system is frequent engine starting, which cannot, will not affect its resource. And the predicted result of fuel economy for motorists is no more than 8 percent. This is an ideal option; in practice, the savings are even smaller. What kind of fuel economy can we talk about when buying a premium car!
Typically, cars are equipped with the system by default, so its real cost is difficult to calculate. For independent companies, its installation will cost 30,000 rubles. It’s easy to calculate that to justify this amount, you need to drive along the central streets of the city during rush hour for more than one year and stand in long traffic jams.
Let's assume that Start-Stop will save 200-300 ml of fuel per 100 km of travel. We travel approximately 30,000 km per year. As a result, the savings for the car enthusiast will be 60-80 liters of fuel. Think for yourself. If you often drive around the city, the effect will be even greater. When driving on the highway, the meaning is lost. And at traffic lights with a delay of 120-140 seconds, you can turn off the engine yourself.
Cars with a start-stop system do not have a regular battery. It has increased capacity and is able to support more charge-discharge cycles. Finding a replacement for him is not easy. You can supply the original, but it is very expensive, or look for a substitute, which is also not easy. For example, on some cars, before replacing a given battery, you need to perform a number of manipulations. For example, register it in the electronic unit of the car and reset the age of the battery and the number of engine starts. Those. make friends between the battery and the “brains” of the car.
The Start-Stop device is an expensive toy for car enthusiasts. It is equipped with many cars in the database that are more expensive than a million. You can personally check the advantages and disadvantages from your own experience. If you don’t like it, you can always turn it off using a button on the instrument panel. But there is no point in choosing a car, given the presence of this option.