End to end automotive efficiency
Efficiency of cars measured often measured by fuel efficiency is misleading. Because it only considers the user end efficiency. Today an average petrol engine is about 35% percent efficient at its best point, but is only 20 percent efficient in urban driving. But many short trips with cold engine, amplified by cold weather and aggressive driving, significantly worsen fuel consumption, as do substantial time spent with the engine idling and losses in transmission. These real-world driving phenomena reduce the engine’s average efficiency so that only about 10 percent of chemical energy stored in the fuel tank actually drives the wheels. Hence out of the 100 units of chemical energy given to the car, only 10 units are available to drive the car.
Posted by sandeep