about alternator amp outage and fuel consumption
about alternator amp outage and fuel consumption
(OP)
g'day team,
hey i'm a rank novice with a maybe silly question?
not knowing anything about altenator amperage output and the fuel consumption of a vehicle i need to ask a question?
if one where to take an extra 2amps above what is used in the normal opperation of a car, how much extra fuel would say a 1300cc 4 cyl' motor use driving the altenator to supply that extra power?
me assuming here that the larger a motor gets the less the impact of supplying that extra 2 amps?
i have tried googles seeking some answer with no luck, the question comes out of statement made on another forum about a massive use of extra fuel to provide that 2 amps of power.
many thanks in advance for any help.
len
hey i'm a rank novice with a maybe silly question?
not knowing anything about altenator amperage output and the fuel consumption of a vehicle i need to ask a question?
if one where to take an extra 2amps above what is used in the normal opperation of a car, how much extra fuel would say a 1300cc 4 cyl' motor use driving the altenator to supply that extra power?
me assuming here that the larger a motor gets the less the impact of supplying that extra 2 amps?
i have tried googles seeking some answer with no luck, the question comes out of statement made on another forum about a massive use of extra fuel to provide that 2 amps of power.
many thanks in advance for any help.
len





RE: about alternator amp outage and fuel consumption
len
RE: about alternator amp outage and fuel consumption
RE: about alternator amp outage and fuel consumption
i can see that 24 watts is around 1/3 of a horsepower is that right?
but not going to be able to go further as i have no idea how much fuel that much horsepower might use in the everyday application of a motor cars use?
len
RE: about alternator amp outage and fuel consumption
750/24 = 31.25
RE: about alternator amp outage and fuel consumption
Alternators aren't 100% efficient, but oddly enough the engine will be following the Mills line and the alternator would do the same and so is going to be very efficient at generating extra power.
So as a number, much less than 1% difference, but probably a bit more than 0.3%.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: about alternator amp outage and fuel consumption
ta
len
RE: about alternator amp outage and fuel consumption
in the real world you will never notice the difference
bob g
www.microcogen.info
RE: about alternator amp outage and fuel consumption
thanks for that yes looks like from all teh answers i got that the issues of 2amps would be all but unnoticable.
len
RE: about alternator amp outage and fuel consumption
MS
RE: about alternator amp outage and fuel consumption
Smaller motorcycles and some older large motorcycles used a somewhat wasteful control scheme but any automobiles that I know about use an efficient active control scheme for the alternator.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: about alternator amp outage and fuel consumption
I actually spent some time in South Korea last year, and noticed that a high precentage of the cars had automatic headlight dimming -- they'd only go to full brightness on a road with no street lighting at all. In the city where the street lighting was brighter, or on their main highways, the headlights would all dim down to a level that made me think they had alternator problems... Still enough to improve one's ability to notice the car, though.
I also spent an entire two weeks without seeing a single incandescent light bulb in a building...
You're right, I've thought often about how much gasoline we could all save by improving headlight efficiency, I bet it's huge when the number of cars is considered.
Good on ya,
Goober Dave
RE: about alternator amp outage and fuel consumption
But the headlights dimming reminded my of Canada. New cars must have daytime running lights. Some use dedicated lamps, some use the headlights at reduced brightness. Many new cars have automatic headlight control. With the right intensity of street lights it is possible that Canadian cars would do the same. But we either have a higher cut-in point on the headlight control or our street light are not as bright. You do see that effect in Canada when cars enter a tunnel or snow shed and the reduced light kicks the headlights from "Daytime" to full night-time brilliance.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: about alternator amp outage and fuel consumption
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RE: about alternator amp outage and fuel consumption
24 watts of electrical energy take 50 watts of kinetic energy away from the motor.
RE: about alternator amp outage and fuel consumption
RE: about alternator amp outage and fuel consumption
That's the way accounting driven engineering works.
Bill
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"Why not the best?"
Jimmy Carter