Re: Questions about fuel consumption at engine level Quote:
Originally Posted by esteem_lover You are right, that is true for ghat sections, not our city roads, right ? |
Always remember what a gearing system does. It manipulates the load as seen by the power source. In this case the power source is the engine and the load is the car's weight.
Also remember what newton said, energy is only required to accelerate/decelerate and not to maintain constant speed.
So combining these two when we are in lower gears (1st/2nd) the engine is seeing a very low load (actually just divide the weight of the car by the gear ratio and this shows the actual weight as seen by the engine) and hence is able to rev easily to 2K/3K where it generate enough torque.
As you gain speed, you need lesser and lesser energy to accelerate and hence you can present a larger load to the engine and reduce the rpm while increasing the speed.
(Think about someone at home asking you to move a big sofa/bed. The initial energy required to get it to move is high. Once it moving to keep it moving its always less. Well in cars we we have gears but at home we just need to push push push )
The above is simplistic and a basic understanding. There are other complexities to worry about such as wind resistance at higher speeds, optimum rpm ranger where the engine is most efficient etc)
Last edited by ash_blore : 2nd August 2012 at 10:47.
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