Power and mileage
Power and mileage
(OP)
Hi,
I am a mech eng. stud..I was wondering about what sort of relation existsbetween power and mileage and how do we get both the benefits from 1 engine
Could anyone possibly help me out
I am a mech eng. stud..I was wondering about what sort of relation existsbetween power and mileage and how do we get both the benefits from 1 engine
Could anyone possibly help me out





RE: Power and mileage
RE: Power and mileage
Gas engines are theoretically the most efficient at full throttle. At full throttle there is little or no vacuum holding them back. All of the power goes out the crankshaft. This is why a small gas engine at full throttle will always have better economy than a big engine at half or quarter throttle.
There is other power dissipation at bearings, cylinders and assesories, but I believe this is negligible compared to the vacuum affect.
RE: Power and mileage
RE: Power and mileage
RE: Power and mileage
The octane rating of a fuel is derived from a test engine running on a mix of isoheptane and isooctain. Isoheptane will detonate as soon as you look at it! Isooctain is added untill the engine runs without detonation. A gasoline with the same anti knock qualities is given the octain rating with is the ratio of isoheptane and isooctain of the comparison test fuel.
For your information...
Nigel Waterhouse
n_a_waterhouse@hotmail.com
A licensed aircraft mechanic and graduate engineer. Attended university in England and graduated in 1996. Currenty,living in British Columbia,Canada, working as a design engineer responsible for aircraft mods and STC's.
RE: Power and mileage
Average consumption = m
Engine thermal efficiency = Te
Engine Mechanical Efficiency = Tm
Power available at the transmission = Q.m.Te.Tm
Transmission efficiency = Tt
Distance traveled to burn m mass of gasoline = d
Average mass of the car + Passengers = M
On a flat road energy required = M.d = Q.m.Te.Tm.Tt
Therefore m = (M.d)/Q.Te.Tm.Tt