dupedcyclist

Could someone offer a guess on the fuel costs for using headlights and
foglights while driving?

2003 Excursion, stock lamps. V10

I am guessing that the energy draw is around 1/4 MPG.

steve barker

check out the facts at www.lightsout.org


--
Steve Barker

snoman

Good question. 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.
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TheSnoMan.com

joe

An independent estimate is easy to do - If you know the wattage of the
lamps.

100 Watts is 341 BTU/hr. Gasoline contains over 100,000 Btus per gallon,
but your engine is only 30% efficient. Let's just call that 30,000 Btu's per
gallon that you can use. So 100 watts is going to cost you 341/30,000 =
..01 gallon per hour.

MPG math is hard to do, because it's not a consumption figure. Let's do it
this way: If you drove an hour at 70 mph and got 12 mpg, then you'd be
burning 5.833333 (lots of 3's) gallons per hour. Add the.01 and you have
5.84 gallons per hour, over 70 miles. 70/5.84333333 That comes out to 11.98
mpg.

So in that case 100 watts is about .02 mpg

big al

Facts?? That link is to a bunch of pure BS.

Al

big al

Holy crap. I'm charging my cell phone at home from now on

Al

snoman

I bet you do not believe in global warming either nor that oil supply
is limited. Thats the problem when you cannot "think outside your box'
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TheSnoMan.com

snoman

Not bad logic but 30% is a bit to generous at cruise and your do not
consider that alternator is not 100% efficent either. BTW gas has
from about 115,000 to 125,000 BTU's to a gallon so we will average it
at 120,000 (the lower number is E10 or 10% alchol) There is about 2800
BTU in a HP to. If your vehcile uses say 40 HP to cruise figure on 40
times 4 (averaging 25% efficency) or 160 HP input needed. next 160 x
2800 equals 448000 BTU's needed or about just under 4 gallons a hour.
If we take that engine is susing approx 500 ounces of fuel per hour
(128 x 4) and factor in about 4 more ounces for another 380 BTU/hr
(120,000 dived 128 equal BTU per ounce) The added usage in this
senerio would be about .8% or less (4 oz / 500 oz) so at say 15 MPG
(assuming 60 mph cruise at 4 gallons a hour) it would be around or
under .12 MPG. (15 x .8%)

With a car that gets 30 or 40 MPG it would be more noticable because
the energy needed for lights would be constant but a smaller car woul
need less to roll and use less fuel and when you used say 2 GPH or 256
oz you would divide 256 into 4 and get 1.5 % or about a .45 MPG or
less penalty at 30 MPG.
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TheSnoMan.com

samstone

"(The energy required to power the DRLs is not free. It is not surplus energy that is just
"available" from the vehicle's engine. Various estimates place the reduction in overall
fuell efficiency at 0.25 - 0.5 mpg, and cost estimates range from $5 - $15 per year. GM
estimates the annual cost of DRLs at less than $10 per vehicle per year.)"
I copied that from the lightsout site and those numbers are in line close enough with
other numbers figured here in this post so the site isn't 'PURE' bs is it?

big al

This coming from you. Well, thanks for allowing me to answer you BEFORE you
crucify me. My head is in a box and yours is way up your ASS! By the way,
how much is the bet and when do you pay me.

Al