Whats your definition of a "efficient engine?"

[Qr25vet]

As said above...whats your own definition of a "efficient" engine? as nowadays everyones talking abt efficiency blah blah blah...

Edited June 10, 2010 by Qr25vet

[Cerano]

at least 100bhp per litre

[Yeobh]

Heat engine is still only converting about 30% of the chemical energy to mech energy, about 70% of the energy is wasted as heat dissipated via the cooling system.

[Octopus]

As said above...whats your own definition of a "efficient" engine? as nowadays everyones talking abt efficiency blah blah blah...

 

I think mileage is a more suitable guage. Because efficiency is the amount of energy (petrol) needed to perform a useful work (travel).

 

If a car has big horsepower but burn petrol and achieve little mileage, then its inefficient.

If a car has little horsepower but use little petrol to travel great distance, then its efficient.

[Cerano]

I think mileage is a more suitable guage. Because efficiency is the amount of energy (petrol) needed to perform a useful work (travel).

 

If a car has big horsepower but burn petrol and achieve little mileage, then its inefficient.

If a car has little horsepower but use little petrol to travel great distance, then its efficient.

 

that thermodynamical efficiency.

 

if we're talking bout displacement efficiency then yes its bhp/litre

[Octopus]

that thermodynamical efficiency.

 

if we're talking bout displacement efficiency then yes its bhp/litre

 

I feel the basic function of car is for transportation purposes. Hence, mileage is more suitable for judging the efficiency.

If you talking about racing, then perhaps bhp/litre may apply.

[Cerano]

I feel the basic function of car is for transportation purposes. Hence, mileage is more suitable for judging the efficiency.

If you talking about racing, then perhaps bhp/litre may apply.

 

not so much racing.

 

i think more of roadtax kekeke volumetric efficiency.

[Ladykillerz]

both. =x

[Kiadaw]

Heat engine is still only converting about 30% of the chemical energy to mech energy, about 70% of the energy is wasted as heat dissipated via the cooling system.

 

Whats heat engine?

 

Anyway, for 4 stroke engine, only 1 out of the 4 strokes is doing work, hence, petrol engine are consider very inefficient. Not to mention losses due to sound & heat, as well as to drive the components.

[Thedream]

I think this is a tricky question

 

Just like Power is derived from Torque (Power = Torque x Angular Velocity), Mileage is derived from Power (i.e. it is power that pushes the wheels to achieve Mileage.)

 

The difference between BHP per Litre and Mileage per Litre is transmission loss. Mileage per Litre would be an equivalent comparison to WHP per Litre.

 

But since the question is "Efficient Engine," then I think the answer can only be "BHP per Litre."

 

Unless the question is "Efficient Transmission" or "Efficient Car," then the answer would be Mileage per Litre.

 

But actually if you're referring to what people loosely refer to when they say "efficiency," I think they are referring to Fuel Efficiency, whereby the answer would then be "Mileage per Litre."

 

Sorry for "thinking too much"

[Renegade777]

 

Efficient engines to me has to be reliable, step accelerator and easily move machiam very light, not too expensive and not too cheap and lastly sip petrol. Does it sound like a Toyota ?

[Akari_ph]

Efficiency is always compare between ideal and actual situation. eg. there will be only 30% efficiency, when ideal engine can produce 100bhp and actual only can produce 30bhp. Same go with comsumption.

 

Personally, I prefer higher BHP/L with good mileage.

[Seaweed]

minimum input....maximum output...simple...

[inlinesix]

100NM/L @ 2.5k - 3.5k RPM

10km/L average FC

[Qr25vet]

something just popped into my mind...am i right to say that the rotary engine or wankel is one of if not the most efficient engine? (in theory)

[Qr25vet]

anyways i just feel that its very very subjective...it just depends if u're a petrolhead or an economical minded motorist :P Like for instance...Do u think that a 5L V8 coughing out only 170 BHP or a 2L engine doing just that is more efficient? i prefer to think in a sense of squeezing out as much power from every drop of petrol...

[Cerano]

anyways i just feel that its very very subjective...it just depends if u're a petrolhead or an economical minded motorist :P Like for instance...Do u think that a 5L V8 coughing out only 170 BHP or a 2L engine doing just that is more efficient? i prefer to think in a sense of squeezing out as much power from every drop of petrol...

 

honestly speaking...

 

no true car enthusiast will be a fuel savings lover.

 

we just love to burn fuel. or else why people buy a 6.3L V8 that runs like 4-5km/L

[Cerano]

something just popped into my mind...am i right to say that the rotary engine or wankel is one of if not the most efficient engine? (in theory)

 

if you want the greatest BHP/L other than forced induction then yes (:

 

but rotarys cannot match the torque from FI engines