Four stroke is more fuel efficient than two stroke because 2 stroke engine doesn’t burn entire fuel. … In a 2 stroke petrol engine, due to open ports the fuel efficacy is very low as compared to 4 stroke engines.
Which is more efficient SI or CI engine?
Thermal efficiency: Due to lower compression ratio, maximum value of thermal efficiency is lower in an S.I engine compared to that of C.I. 7… Weight : S.I engines are generally lighter in weight due to their lower peak pressures as compare to C.I engines that are generally heavier, due to higher peak pressure.
Which engine has more mechanical efficiency?
Real diesel engines are of course considered to be more efficient that Otto cycle engines; one reason being that diesel engines typically operate at higher compression ratio and the expansion ratio from even the later stages of heat release can still be considerably higher than that of most real Otto cycle engines.
Why is 55 mph the most efficient speed?
The most efficient speed for electric cars is closer to 15-20 mph versus 55 mph for ordinary cars. This is because the losses at low speeds for ordinary cars has to do with the construction and inefficiency of the gas ICE. Directly to the question at hand – they also give the sources of losses over the range of speeds.