what are profit margins Gas vehicles mainly include liquefied petroleum gas vehicles (LPG vehicles or LPGV) and compressed natural gas vehicles (CNG cars or CNGV). As the name suggests, LPG cars are fueled by liquefied petroleum gas (LPG) and CNG is powered by compressed natural gas. The CO emission of gas vehicles is more than 90 percent less than the gasoline car, the hydrocarbon emission reduction is more than 70 percent, and the nitrogen and oxygen emission reduction is more than 35 percent, which is the current relatively practical low emission vehicle. It is easy to draw the conclusion that on the condition that businesses make a profit by exploiting on human resources, falsifying on products and neglecting the after-sales service, they will not success in a long run. Only the businesses thinking in the overall respects can survive and thrive all the time. Accounting earnings include only realized gains, and exclude unrealized gains and losses, the economic benefits will be enterprise's operating earnings and are favorable to the same treatment, regardless of whether they have been implemented. Thus, in general, accounting gains are less than economic gains, and the difference is mainly in the interest.