案例四:某位车主在一次洗车时,对方主动提出免费给他的爱车做一次常规检查,结果查出机油变黑了,建议他及时更换,并向他推荐了店里的几款机油产品,而事实上,他的爱车从上次更换机油到现在才跑了不到2 000 km。解析:显然,这位车主遇到了黑心商家。通常来说,机油在使用一段时间之后,颜色就会变黑,但这并不等于变质。正常情况下,只要用的不是假货,无论任何品牌的机油,其寿命都可以保持在5 000 km以上。只有当车主长期保持不良驾驶习。惯时,如频繁紧急制动,加油过猛致使转速经常在3 000 r/min以上,机油的更换周期才会提前。有经验的技师会通过机油的黏度及受污染程度来判别是否需要更换,而非单纯观察机油的颜色变化。 Case four: a car owner in a car wash, the other voluntarily proposed to his car to do a routine examination, the results found black oil, suggesting that he promptly replaced, and recommended to him some of the store’s oil products In fact, his car ran less than 2 000 km from the last change of engine oil. Analysis: Obviously, the owner met a black heart merchants. In general, the oil will turn black after a period of use, but this does not mean deterioration. Under normal circumstances, as long as the fake is not used, regardless of any brand of oil, its life can be maintained at 5,000 km above. Only when the owner of the poor long-term driving habits. Inertia, such as frequent emergency braking, excessive fueling so that the speed is often more than 3 000 r / min, the oil replacement cycle will advance. Experienced technicians use the viscosity and contamination levels of oil to determine if they need to be replaced, rather than simply observing the color change of the oil.