D1 is the first domestically-developed diesel engine oil specification in China, featuring significant local technological characteristics and having milestone significance in the industry.

Copton, as one of the core members of the "China Engine Oil Standard Development and Innovation Alliance (CLSAC)", together with other members of the alliance, through extensive basic research, technical promotion and verification tests, completed the development of the first D1 specification with complete independent intellectual property rights.

During the development of the D1 specification, over 60,000 hours of bench tests were completed, 3,300 tons of fuel were consumed, and more than 30 "critical technology bottlenecks" were successfully overcome. This completely broke the long-term reliance on international standards such as API, marking a historic leap for the Chinese lubricant industry from "following standards" to "leading technology".