6 for passenger cars. According to the national regulations,
1 stands for length, for example, this is 1m, and 12 stands for 12m. If it is less than 1m, for example, 8 of ZK6831 stands for length, and 3 and 1 stand for one digit after the decimal point or the number specified by the manufacturer, but it is not necessarily accurate. For example, ZK612HG stands for 11. EV stands for pure electricity or oil or natural gas and electric hybrid, and NG stands for gas vehicle or gas-electric hybrid.