In order to cope with fuel consumption standards and emission regulations, a large number of cars are equipped with an automatic start and stop function. This thing can really save fuel, but the side effects are also obvious. First, the work is not smooth, the use experience is not good, and the durability of some components is also A test, mainly battery and starter motor. Some owners also vaguely felt that frequent flameouts are not good for the engine, but how bad it is, but it is not clear.
▲Please remember this button, you will definitely use it.
The so-called automatic start and stop is to automatically turn off when the car is stopped (such as waiting for the red light), and automatically ignite when the foot leaves the brake pedal. When the car is parked, the engine idles also consumes fuel and exhausts, if there is automatic The start-stop function reduces the idle speed and the fuel consumption is definitely reduced.
How much can it be reduced? According to the data provided by various auto manufacturers, fuel consumption can be reduced by 3% to 10%, and individual manufacturers claim to be reduced by up to 12%. The difference is so large, mainly in different vehicle environments, automatically start and stop work. The degree of hard work is different.
If it is in a congested environment in the city, the number of automatic engine stalls is high, and the fuel-saving effect is more obvious. If you run to the highway, this function is useless; for example, when driving in summer, to ensure the air conditioning of the car. Work (air conditioning is more expensive, it is not possible to rely on battery power after the car is turned off), the number of automatic start and stop is greatly reduced, and the impact on fuel consumption is not great.
According to the American automobile media Edmunds's use of MiniCooper's actual measurement, in the section where the automatic start-stop usage rate is high, the air conditioner can be turned off to save fuel by 9.5%, and the air conditioner can only save 2.9%.
▲ According to Edmunds's actual measurement, air conditioning has a great influence on the effect of automatic start-stop fuel saving.
This is not the focus of our discussion. Many car owners are not interested in this oil in the province, but they are particularly concerned about the automatic start and stop will not 'fee the car', will accelerate the loss of the car.
The automatic start-stop will cause the engine of the car to be frequently turned off and started. According to the head of the bearing development of the famous engine parts supplier FederalMogul (Feimen), the engine of a car will start 50,000 times during the life cycle, and once it joins Automatic start and stop function, the number of starts may increase by 10 times, to about 500,000 times.
The number of engine starts has increased several times. The first thing that people think of is that the battery and the starter motor (motor) can't bear it. In fact, the car, the battery and the starter motor equipped with the automatic start-stop function are both 'enhanced versions', which are better than ordinary cars. More powerful, at present, there are not many problems with starting the motor, but many batteries are laid off in advance in two years or so, so that the owners are sorry.
The automatic start-stop is a special battery, the price is much more expensive than the ordinary battery, the popular brand car also needs to use thousands of pieces, the luxury brand car can reach three or four thousand yuan. This kind of battery is hanged in advance, the cost of replacement Will make the owner feel a pain.
Compared to the engine, the starter motor and the battery are small parts, and it's no big deal to change one. Some car owners really worry about whether the engine will wear excessively.
The bad news is that the engine is likely to wear excessively, mainly the crankshaft.
▲First understand the main mechanical parts inside the engine
The curved track is one of the most important parts inside the engine and one of the 'heaviest' parts. Every time it starts, the task of starting the motor is to drive the heavy crankshaft up, and then the whole engine starts to work. .
After the engine is ignited, each cylinder piston reciprocates up and down, and then the crankshaft rotates through the connecting rod. The connection between the crankshaft and each piston connecting rod and the engine casing is combined by a sliding bearing called 'bearing bushing'. When the engine is working, the crankshaft has to be turned thousands of revolutions in one minute. The lubrication of these joints is very important. Once the lubrication is not good, the wear will be intensified.
▲The piston moves up and down, the crankshaft rotates
When the engine is running, the crankshaft and the bearing bush (sliding bearing) are not in direct contact, and a thin layer of oil film is interposed. After the flame is extinguished, the oil pump no longer supplies oil pressure, and the crankshaft is in contact with the bearing bush. At the moment of restarting, the direct contact between the metal and the metal will cause wear. With the car equipped with the automatic start-stop function, the number of engine starts is greatly increased, and the wear on the crankshaft will definitely be more severe.
▲At rest, there is no lubrication between the underside of the crankshaft and the bearing bush
Now, there are two ways to reduce the crankshaft wear. One is to add a smooth coating on the 'bearing tile' surface, so that the bearing bush has its own lubricating ability; the second is to improve the oil performance, and rely on the additives in the oil to improve the lubrication level.
▲The crankshaft and the bearing bush may be abnormally worn if the lubrication is not good.
We are not sure whether all the cars with start-stop function and the crankshaft bushing inside the engine have increased the lubrication coating. Therefore, we can use high-performance lubricating oil to prevent abnormal wear of the crankshaft. However, this way, The petrol money under it is spent on the oil.
Fortunately, the automatic start and stop function of most cars can be manually turned off. Some cars can also disable this function by 'brushing the computer'. If you are worried about the battery hangs too early, or worry about the crankshaft wear, or simply feel that you can't stand the automatic Start and stop the 'harassment', then turn it off.
▲ don't like to use automatic start and stop, then turn it off.
Mazda's 'i-stop' intelligent automatic start-stop technology claims to be the world leader. i-stop can accurately control the position of the piston when the engine is stopped. When restarting the engine, directly select the appropriate cylinder fuel injection ignition, no longer drive the starter motor, battery Just igniting the ignition without driving the starter motor. Mazda believes that his i-stop is advanced enough and smooth enough, but it has not been introduced to the US market. The reason is very simple. Mazda found in the United States that most people will turn off automatically after getting on the train. Stop function, because they are annoyed that this thing frequently turns off the ignition, affecting the driving mood.
Maybe the American oil is too cheap, so the owners don't care about saving the oil. But whether it's care about fuel consumption, there is a situation that must be remembered to turn off the automatic start and stop function. Now it's rainy season, the city flooding event In the high-incidence period, if the engine is wading on the road, it is very troublesome to turn off the engine. In this case, do not let the automatic start and stop to mess up.
