Good quality. Yifeng pure brand engine oil is very pure, with bright color and good quality. The price is 9 yuan per liter, which is more expensive. Guangfeng engine oil is dull and not pure enough, and the price is 7 yuan per liter, which is cheap. Shandong Guangfeng Special Oil Products Co., Ltd. was established in 1998, which is a middle and high-grade industrial lubricants professional enterprise integrating lubricant production, research and development, storage and transportation, sales and service.