# how much fuel does a 250cc engine consume per minute?

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5 years ago
***WARNING***
LOTS and LOTS of assumptions in these calculations, but I figure pretty close.

250cc engines at 3600rpm put out what I found on the net to be about 7-8hp.

on the high side, say 10hp

A watt is a joule-second.

that's 7500 joules/second, or 450kJ/minute

Wikipedia says:
"Gasoline contains about 35 MJ/L (9.7 kW·h/L)"
and
"most engines retain an average efficiency of about 18%-20%"

so to output 450kJ/minute the engine has to consume about 2.25MJ of gasoline/minute (wastes 1.8MJ/minute as heat)

Gasoline @ 35MJ/L and engine consumes 2.25MJ/m =
35/2.25 = 15.6 minutes/liter or 0.0643 Liters per minute.
lemonie5 years ago
At what RPM?
With what fuel?
What type of engine?

L
lohithg (author)  lemonie5 years ago
at RPM of 4000 and the fuel is diesel and it is a four stroke engine
5 years ago
If it's a specific engine could you name it?
What I should have thought to ask is "what output horepower?" See, 4000 RPM on "engine only" won't consume the same amount of fuel as 4000 RPM at full load in "drive".

L
lohithg (author)  lemonie5 years ago
I am not willing to know the fuel consumption of a specified engine but the average consumption of diesel per minute.
5 years ago
You got a good answer from Frollard, I hope that's done for you there.

L
Burf5 years ago
Not enough information:
Two stroke or four?
3.5 HP work duty engine or 45 HP motocross screamer?
Constant load or variable power output?
Fuel type?
steveastrouk5 years ago
0, when its off.
rickharris5 years ago
So much depends. This isn't really possible to answer.

Look up some motor bike fuel figures.