A statistic of automatic transmission maintenance shows that more than 90% of the wear of engine components is caused within 3 minutes after cold start. The main reasons for the need for hot cars are as follows.

1.發動機剛剛啟動時，供油系統溫度尚低，無法達到工作溫度(90~100攝氏度)，汽油不能全霧化，這時的汽油還處于液態，如果強行加速行駛，因為油氣混合比過高，會令油耗升高、動力不足，而且汽油燃燒也不好。

1. When the engine is just started, the temperature of the oil supply system is still low and cannot reach the working temperature (90 ~ 100 ℃), and the gasoline cannot be fully atomized. At this time, the gasoline is still in liquid state. If you forcibly accelerate the driving, because the fuel air mixing ratio is too high, the fuel consumption will increase, the power will be insufficient, and the gasoline combustion will be poor.

2.變速箱中的潤滑油此時也都因重力作用，囤積在下方，這時如果把車開不夠造成的。只有行車時讓變速箱齒輪運轉起來，才能將所以根本達不到潤底部潤滑油帶起，潤滑上部。如果只在原地用怠速熱車，由于變速箱沒有油泵，所以根本達不到潤滑作用。

2. The lubricating oil in the gearbox is also stored under the action of gravity. At this time, it will be caused if the car is not driven enough. Only when the transmission gear is operated during driving can the lubricating oil at the bottom which can not be lubricated at all be brought up to lubricate the upper part. If you only use idle speed to warm up the car in place, the lubrication effect can not be achieved because there is no oil pump in the transmission.

3.車輛在經過長時間停放后，發動機內的機油會集中在下方油底殼內，各部件表面的潤滑油膜基本上已經消失，這時啟動發動機，其上半部分是沒有機油的，需要大約30秒的時間，機油泵才能將機油輸送到發動機活塞、連桿和曲軸等需要潤滑的部件。

3. After the vehicle is parked for a long time, the oil in the engine will be concentrated in the lower oil pan, and the lubricating oil film on the surface of each component has basically disappeared. At this time, when the engine is started, the upper part of the engine is free of oil, and it takes about 30 seconds for the oil pump to deliver the oil to the engine piston, connecting rod, crankshaft and other components that need lubrication.

現在的汽車一般都使用電子噴油嘴，不同于老式的化油器車型，電噴車供油系統由ECU控制，不受空氣流速和溫度的影響，燃油霧化程度高，發動機啟動后很短時間內就可以達到穩定的怠速。所以熱車無需時間太長，只要機油壓力升高，水溫達到50攝氏度左右就可以了。一般在車發動后等半分鐘到一分鐘就能讓發動機的機油達到各個部件表面。

Today's cars generally use electronic fuel injection nozzles. Different from the old carburetor models, the fuel supply system of EFI vehicles is controlled by ECU, which is not affected by air flow rate and temperature. The degree of fuel atomization is high, and the stable idle speed can be achieved in a short time after the engine is started. So it doesn't take too long to warm up the car. As long as the oil pressure rises and the water temperature reaches about 50 degrees Celsius. Generally, the engine oil can reach the surface of each component after waiting for half a minute to one minute after the car starts.

需要注意的是，除了需要時間讓機油覆蓋的零件之外，發動機在持續工作之前還需要達到定的工作溫度。一般發動機從環境溫度達到工作溫度需要7到8分鐘,但這個過程無需待在原地，只要不以高速行駛就可以。發動機長時間怠速會增加油耗和積炭，不利于。

It should be noted that in addition to the parts that need time to be covered with oil, the engine also needs to reach a fixed operating temperature before continuous operation. Generally, it takes 7 to 8 minutes for the engine to reach the operating temperature from the ambient temperature, but this process does not need to stay in place, as long as it does not drive at high speed. Idling the engine for a long time will increase fuel consumption and carbon deposition, which is not conducive to environmental protection.

綜上所述，自動變速箱維修告訴我們熱車是比較重要的，所以在這里提示大家，做好相關的注意事項。

To sum up, the maintenance of automatic transmission tells us that hot car is more important, so here we remind you to do a good job of relevant precautions.