News0 min ago
Petrol Consumption
I`ve read that it increases a vehicles petrol consumption if you run it with headlights on, as in daytime driving, which has been proposed by some agency study group.
Is this true, as I can`t see that it does, but maybe I`m missing something? (apart from intelligence I mean!)
Is this true, as I can`t see that it does, but maybe I`m missing something? (apart from intelligence I mean!)
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For more on marking an answer as the "Best Answer", please visit our FAQ.Yes of will increase fuel consumption having your lights on, simple rule of physics, you can't create energy from nowhere, the extra energy needed to run your headlights needs to come from somewhere and the only place it can come from on a car is your fuel tank.
Though it's a pretty small increase and probably far outweighed by the increase in safety from having your lights on
Though it's a pretty small increase and probably far outweighed by the increase in safety from having your lights on
Where exactly did you get this from?
I really cannot believe that any study group woukld suggest this and I can't see anything after a quick flit around the net.
Sounds to me like something made up to annoy the sort of people who'd believe anything about Government think tanks.
Seems to be working eh?
Chuck's right in theory but in practice complicated systems like cars have an awful lot of power losses that are unpredictable in nature. You'd never spot the loss in fuel consumption from the headlights over the rest of the "noise".
Any Government comittee's first port of call would be air conditioning in cars.
I really cannot believe that any study group woukld suggest this and I can't see anything after a quick flit around the net.
Sounds to me like something made up to annoy the sort of people who'd believe anything about Government think tanks.
Seems to be working eh?
Chuck's right in theory but in practice complicated systems like cars have an awful lot of power losses that are unpredictable in nature. You'd never spot the loss in fuel consumption from the headlights over the rest of the "noise".
Any Government comittee's first port of call would be air conditioning in cars.
Daytime running lights may become a legal requirement for vehicles manufactured after a certain date:
http://www.dailymail.co.uk/news/article-106124 5/Now-Europe-wants-headlights-ALL-day--inflati ng-fuel-costs-160-year.html
And it does increase fuel costs, although one possibility is the introduction of LED lights for daytime, which will use less fuel
http://www.dailymail.co.uk/news/article-106124 5/Now-Europe-wants-headlights-ALL-day--inflati ng-fuel-costs-160-year.html
And it does increase fuel costs, although one possibility is the introduction of LED lights for daytime, which will use less fuel
It will certainly make motorcyclists less visible, if everyone has their headlights glaring.
True story - this headlight always on is a legal requirement in Estonia. A UK lorry driver had his articulated truck stopped by police in broad daylight as they needed to check he had his lights on. They couldn't tell from looking as he passed by because of the glare of the sun.
True story - this headlight always on is a legal requirement in Estonia. A UK lorry driver had his articulated truck stopped by police in broad daylight as they needed to check he had his lights on. They couldn't tell from looking as he passed by because of the glare of the sun.
Having read the two articles there are many comments against using headlights in the daytime but non of the comments are quantified,
It will use more fuel but how?
Looking for lights instead of pedestrians is no different than looking for cars instead of pedestrians.
There is a small risk that some drivers will forget to switch on their headlights at night. What !!!!!
'This directive will kill a lot of motorcyclists. They use daytime lights to make them easier to see but if cars are using them as well, motorbikes will blur into the background.'
No more than a car with its headlights on will.
It appears many organisations are against this proposal but are coming up with ludicrous reasons to oppose it
It will use more fuel but how?
Looking for lights instead of pedestrians is no different than looking for cars instead of pedestrians.
There is a small risk that some drivers will forget to switch on their headlights at night. What !!!!!
'This directive will kill a lot of motorcyclists. They use daytime lights to make them easier to see but if cars are using them as well, motorbikes will blur into the background.'
No more than a car with its headlights on will.
It appears many organisations are against this proposal but are coming up with ludicrous reasons to oppose it
thrower,
lights, in-car entertainment, air conditioning all use more fuel
Read Step 4 here:
http://www.ehow.com/how_2264063_fuel-efficient ly-better-gas-mileage.html
lights, in-car entertainment, air conditioning all use more fuel
Read Step 4 here:
http://www.ehow.com/how_2264063_fuel-efficient ly-better-gas-mileage.html
Right so the think tank actually wants to introduce headlights during the day to reduce accidents not to ban it to save petrol.
This makes more sense.
Presumably the Jeremy Clarkson clones are up against it simply because it comes from the EU.
The best arguments seem to be:
People will forget to switch on their head lights
There will be confusion with headlights
and apparently
It'll use more petrol
Sad really.
The electric system runs off of a combined system of the battery and alternator.
The alternator has a regulator which controls the output of the regulator so as not to overcharge and blow up your battery.
On modern regulators the field current is adjusted which means that when the alternator is charging the battery it is having to push against ever so slightly more magnetic field to do so - hence requiring the engine to supply ever so slightly more power to stay at the same rev count.
But as I said before this is almost certainly so small that it's lost in the other variables.
This makes more sense.
Presumably the Jeremy Clarkson clones are up against it simply because it comes from the EU.
The best arguments seem to be:
People will forget to switch on their head lights
There will be confusion with headlights
and apparently
It'll use more petrol
Sad really.
The electric system runs off of a combined system of the battery and alternator.
The alternator has a regulator which controls the output of the regulator so as not to overcharge and blow up your battery.
On modern regulators the field current is adjusted which means that when the alternator is charging the battery it is having to push against ever so slightly more magnetic field to do so - hence requiring the engine to supply ever so slightly more power to stay at the same rev count.
But as I said before this is almost certainly so small that it's lost in the other variables.
Perhaps further study of the increases in fatalities to pedestrians and cyclists (both motor and pedal) recorded in Poland, Bulgaria and Austria since the introduction of DRL is a worthy exercise.
sigma - the alternator converts mechanical energy into electrical energy. Any charge drawn from the battery needs to be replaced and is "extracted" from the engine; more load on the engine means more fuel required to power it. Have you not noticed the pitch of an engine change when electrical components are activated?
Various DRL studies (including those to promote DRL) show an increase in fuel consumption of around 1% to be reasonably accurate.
http://ec.europa.eu/transport/roadsafety_libra ry/consultations/drl_20060727/drl_trl.pdf
sigma - the alternator converts mechanical energy into electrical energy. Any charge drawn from the battery needs to be replaced and is "extracted" from the engine; more load on the engine means more fuel required to power it. Have you not noticed the pitch of an engine change when electrical components are activated?
Various DRL studies (including those to promote DRL) show an increase in fuel consumption of around 1% to be reasonably accurate.
http://ec.europa.eu/transport/roadsafety_libra ry/consultations/drl_20060727/drl_trl.pdf
I find that difficult to believe.
This report was comiisioned as in investigation into the EU work and appears very partisan.
I'm particularly suspicious of:
a/ This was based on a computer model not experimental data - yet there is absolutely nothing to prevent someone from doing this experimentally.
b/ side lights are 4-5 watts x 4 is about 20 watts electrical
That equates to 0.026 horsepower
If you take a car engine generating some 50HP 1% would be about half a horsepower.
So they are suggesting that there is an efficiency of about 5%
Yet most alternators run at 75-80% efficiency
Put a car on a dynometer and show me a loss of half a horsepower when you turn on the lights.
No?
Funny that
This report was comiisioned as in investigation into the EU work and appears very partisan.
I'm particularly suspicious of:
a/ This was based on a computer model not experimental data - yet there is absolutely nothing to prevent someone from doing this experimentally.
b/ side lights are 4-5 watts x 4 is about 20 watts electrical
That equates to 0.026 horsepower
If you take a car engine generating some 50HP 1% would be about half a horsepower.
So they are suggesting that there is an efficiency of about 5%
Yet most alternators run at 75-80% efficiency
Put a car on a dynometer and show me a loss of half a horsepower when you turn on the lights.
No?
Funny that
Ethel,
I don`t want to be argumentative, but having read step 4 of the link, I`m still not convinced.
The alternator on my car doesn`t `sense` nor is it computerised and programmed, it`s driven by a constantly turning belt. That produces electricity whether you push the accelerator lightly or not and is returned to the battery. Any excess, as I understand it, when the battery is `topped up` is returned to Earth. In other words going to waste. Therefore why should it decrease MPG to turn the lights on, which are powered by the battery? The alternator doesn`t `know` whether the lights are on or off.
I don`t want to be argumentative, but having read step 4 of the link, I`m still not convinced.
The alternator on my car doesn`t `sense` nor is it computerised and programmed, it`s driven by a constantly turning belt. That produces electricity whether you push the accelerator lightly or not and is returned to the battery. Any excess, as I understand it, when the battery is `topped up` is returned to Earth. In other words going to waste. Therefore why should it decrease MPG to turn the lights on, which are powered by the battery? The alternator doesn`t `know` whether the lights are on or off.
Well I don't like to be argumentative either
But you're wrong.
Excess electricity is not returned to earth, and you do have a regulator on your alternator that "senses" the battery's requirements which is related of course to what electrical devices area in use.
I know I had a regulator fail on a car once and it blew the battery apart. (great smell of sulphur)
It was an older car with an external regulator which needed to be replaced. these days they tend to be internal.
Here's a picture and details of an alternator's workings
http://www.autoshop101.com/trainmodules/altern ator/alt109.html
But you're wrong.
Excess electricity is not returned to earth, and you do have a regulator on your alternator that "senses" the battery's requirements which is related of course to what electrical devices area in use.
I know I had a regulator fail on a car once and it blew the battery apart. (great smell of sulphur)
It was an older car with an external regulator which needed to be replaced. these days they tend to be internal.
Here's a picture and details of an alternator's workings
http://www.autoshop101.com/trainmodules/altern ator/alt109.html
Well, to be somewhat argumentative also, no matter how "partisan" it appears to j-t-p, I put more stock in research and analysis by TRL than opinion of any layman.
http://www.trl.co.uk/content/overview.asp?pid= 94
http://www.trl.co.uk/content/overview.asp?pid= 94