What are the consequences of using bad quality engine oil in a car?

The use of bad quality engine oil may lead to a decline in power and increased fuel consumption damage to the three-way catalytic converter and other consequences. The following is a detailed introduction to the method of determining the quality of motor oil: 1, see the packaging: brand-name engine oil on the cap are basically disposable and will be marked on the top of the manufacturer's special mark. 2, smell taste: better quality engine oil is a fully synthetic oil flavor is more fragrant. And when the oil has a clear sour flavor when the oil has deteriorated. 3, fluidity: good engine oil has a very good fluidity and poor quality engine oil in the violent shaking will occur bubbles.