How to Check if a Car is Fuel-Efficient?
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Many car owners often rely on the constant-speed fuel consumption data provided by manufacturers to determine whether a car is fuel-efficient. However, there are many other parameters that affect fuel consumption. Vehicle weight—the most significant factor influencing a car's fuel consumption is its weight. For the same distance traveled, a heavier car requires more work and thus more fuel. It is often said that Japanese cars are fuel-efficient, and besides engine factors, the lighter weight of Japanese cars compared to European and American models is also a crucial reason. Drag coefficient—newer car models often have more streamlined shapes, not only for improved visual appeal but also to reduce air resistance. Many people think of drag as a minor technical parameter, but in practical use, its relationship with fuel consumption is substantial. Generally, at high speeds, the greatest resistance comes from air. Therefore, even a 0.01 reduction in the drag coefficient can make a significant difference in fuel consumption. Engine parameters—generally, for engines of the same displacement, those with more cylinders and more complete combustion are more fuel-efficient. Four-valve engines are more fuel-efficient than two-valve ones, and double overhead camshaft (DOHC) engines are more fuel-efficient than single overhead camshaft (SOHC) engines. Additionally, engines with good linearity—where power increases smoothly and maximum torque is achieved early—tend to be more fuel-efficient. Transmission parameters—for automatic transmissions, more gears mean better fuel efficiency, and continuously variable transmissions (CVT) are the most fuel-efficient.
