The level of car fuel consumption is really not the final say on engine thermal efficiency

We know from our usual driving experience that the fuel consumption of a vehicle is related to driving habits and driving road conditions. Frequent rapid acceleration and braking will cause fuel consumption to be large; The more high-speed runs, the lower the fuel consumption, the longer the urban congestion, and the higher the fuel consumption. In fact, for the fuel consumption rate of the engine, there is a chart called BSFC (Effective Fuel Consumption Rate) for reference.