Lao Zheng, who has been repairing cars for thirty years, raised minor maintenance from 280 yuan to 350 yuan due to rising procurement costs. Regular customers thought it was expensive and turned one after another to a 99-yuan low-price quick repair shop; the fleet canceled the contract, the landlord raised the rent, and Lao Zheng had to take his apprentice and move to the remote south of the city, setting up a shed in the corner of the freight company's yard to start over. He insisted on using original engine oil without changing an extra part, building a reputation among truck drivers with solid craftsmanship. Soon, the low-price shop caused engine damage to multiple vehicles due to non-compliant engine oil, and was investigated and punished by regulatory authorities in accordance with the law. The drivers who left returned one after another, but Lao Zheng did not raise the price by a single penny. A barrel of engine oil reflects people's hearts; operating with integrity,