scotjimland
LIFE MEMBER
- Jul 25, 2007
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I've often wondered how much extra fuel is used when driving with headlights on ..
2 x 65 watt headlights
2 x 21 watt tail lights
2 x 5 watt number plate lights
plus side running lights.. and front side lights.. another 20 watt
adds up to 200 watts .. or about 15 amps , which equates to just over 1/4 hp.
But how much fuel does this use ? Not an easy calculation with so many variables..
anyway.. with this thought, I did a search and found a very interesting paper on the very subject which goes into it in greater detail .. http://mb-soft.com/public/headlite.html
Conclusion being that it does use a small but significant amount of fuel.. but is it worth worrying about.. ?
How many thousands or millions of cars have headlights on without choice and how much does this all add up to ?
I found this on an American motoring forum.. makes you think..
2 x 65 watt headlights
2 x 21 watt tail lights
2 x 5 watt number plate lights
plus side running lights.. and front side lights.. another 20 watt
adds up to 200 watts .. or about 15 amps , which equates to just over 1/4 hp.
But how much fuel does this use ? Not an easy calculation with so many variables..
anyway.. with this thought, I did a search and found a very interesting paper on the very subject which goes into it in greater detail .. http://mb-soft.com/public/headlite.html
Conclusion being that it does use a small but significant amount of fuel.. but is it worth worrying about.. ?
How many thousands or millions of cars have headlights on without choice and how much does this all add up to ?
I found this on an American motoring forum.. makes you think..
It takes about 1/4 HP (give or take) of extra energy
input to alternator to power lights. Given the efficency of a gas
motor that means in theory about a approx 2 to 4 extra ounces of fuel
a hour or so on your V10 or maybe 1/10 th a MPG (at most) or less. It
is a good point though in that when you consider the millions of cars
on the road daily with them that together they could "waste" maybe
500,000 to 1,000,000 gallons of fuel a day (broad range is because of
a guesstimate of units on road) This equals about 12 to 24,000
barrelas of fuel a day or 4.5 to 9 million barrels a year. To put a
different perspective on it, this is also equal to about 25 to 50,000
semi tankers trucks of fuel a year or about 140 tanker truck loads a
day.