如果車輛沒其他異常，又超過3萬公里沒清洗積碳，那很可能就是積碳問題，清洗節氣門、進氣道積碳一般就能恢復原先的油耗。
If there are no other abnormalities in the vehicle, and the carbon deposit is not cleaned after more than 30000 km, it is probably a carbon deposit problem. Cleaning the throttle valve and the carbon deposit in the air inlet can generally restore the original fuel consumption.
In addition to carbon deposition, Jinan Benz auto maintenance personnel believe that there are several common fault points:
1、火花塞性能下降或損壞：這個很好理解，火花塞不好會造成燃燒不充分，自然產生的能量就低，就需要更多的油。同時還會加快積碳的形成，從而形成惡性循環。
1. Spark plug performance degradation or damage: It is well understood that a poor spark plug will lead to insufficient combustion, low energy generated naturally, and more oil is needed. At the same time, it will also accelerate the formation of carbon deposits, thus forming a vicious circle.
2、噴油嘴積碳或損壞：當下瞬時的噴油量是發動機電腦精確計算過的，如果噴油嘴有問題，會對噴油量造成浪費，增加油耗。
2. Carbon deposition or damage of fuel injection nozzle: the instantaneous fuel injection quantity is accurately calculated by the engine computer. If there is a problem with the fuel injection nozzle, it will waste the fuel injection quantity and increase fuel consumption.
3、前氧傳感器故障：前氧傳感器測得的尾氣氧含量，是發動機電腦計算噴油量很重要的一個參數，如果信號不準，容易影響油耗。
3. Fault of front oxygen sensor: the exhaust oxygen content measured by the front oxygen sensor is an important parameter for the engine computer to calculate the fuel injection quantity. If the signal is inaccurate, it is easy to affect the fuel consumption.
4、節溫器或水溫傳感器故障：發動機低溫時，為了更快讓發動機到達工作溫度，會多噴油來應對。如果節溫器一直開啟，導致水溫低，或者水溫傳感器損壞，一直給發動機反饋的信號就是溫度低，那就會一直加濃噴油，從而造成油耗高。
4. Thermostat or water temperature sensor failure: when the engine is cold, more fuel will be injected to make the engine reach the operating temperature faster. If the thermostat is always open, resulting in low water temperature, or the water temperature sensor is damaged, and the signal always fed back to the engine is low temperature, then fuel injection will always be enriched, resulting in high fuel consumption.
The above points can be said to be very common reasons. Also, the air filter element is blocked, the oil viscosity is too high, and the brake wheel cylinder returns poorly. Come to our website if you have any notes http://www.cnjqf.com Consult!
