Dark mornings and evenings Options

[motormad]

I did study physics at school. My teacher looked like Jesus.
In between reading Autocar Magazine and also the Grand Theft Auto San Andreas Guide/Walkthrough , I paid little attention.

An alternator is always running and always generating an amount of charge (and therefore losses from the engine itself) are all things, relatively, uneffected by insignificant loads such as the radio, headlights and what not.

Let's say 14.5v for a healthy one.

While the load through the engine may change depending on electrical load of the car (which is why you may notice your engine revs dipping slightly when you are turning your steering whee, if you have electric power steering for example), this has virtually no effect on your MPG figures. While in theory having your lights on can increase your consumption by 0.0000002mpg you would never, ever, be able to MEASURE THIS in any sort of test.

The biggest problems are huge spikes in power drawn by the vehicle, which you're not likely to get in a normal car, however you may if you have fitted LARGE sub woofers (which I have not) or compressors (which I have), after this initial kick alternator load normally decreases, the engine detects the extra load and increases fuelling and/or idle speed to cope, after which it settles down. Measuring on a multimeter you may see a temporary dip in the voltage being produced as well.

In the real world you will not notice any loss in MPG with your headlights on or off.. I managed my best MPG and tank range while driving at night.... what a fun/boring driving that was. (at no point did I hog the middle lane).

[dannyboy]

from Wikipedia


DRL power consumption varies widely depending on the implementation. Current production DRL systems consume from 5[8] watts (dedicated LED system) to over 200 W (headlamps and all parking, tail, and marker lights on). International regulators, primarily in Europe, are working to balance the potential safety benefit offered by DRL with the increased fuel consumption due to their use. Because the power to run the DRLs must be produced by the engine, which in turn requires burning additional fuel, high-power DRL systems increase CO2 emissions sufficiently to affect a country's compliance with the Kyoto protocol on greenhouse gas emissions.[9] For that reason, low-power solutions are being encouraged[10] and headlamp-based systems are not allowed when DRLs become mandatory in Europe at the beginning of 2011. LEDs and low-power, high-efficacy, long-life light bulbs produce appropriate amounts of light for an effective DRL without significantly increasing fuel consumption or emissions. Fuel consumption reductions of up to 0.5 mpg may be found when comparing a 55 W DRL system to a 200 W DRL system.[11] In 2006, the UK's Department of Transport also found significant reductions in emissions and fuel consumption when comparing a 42 W DRL system to a 160 W full headlight DRL systems.[12] DRL fuel consumption can be reduced to insignificant levels by the use of 8 to 20 W DRL systems based on LEDs or high-efficacy filament bulbs.

[JeffG]

I looked up the meaning of DRL, which was kind of needed to understand that Wikipedia extract.

[dannyboy]

I looked up the meaning of DRL, which was kind of needed to understand that Wikipedia extract.

same term that MM used in post #14.

[Andy Capp]

same term that MM used in post #14.

And it is second nature for some people these days who would just search the Internet if stuck for understanding something!

[Exhausted]

And it is second nature for some people these days who would just search the Internet if stuck for understanding something!

I didn't google anything in my headlight discussions, it is basic engineering. Poor MM still doesn't understand the concept so, whilst this thread was entertaining, he knows best so I must bow to his superior knowledge. Pity I wasted all that time in my formative years. All I needed to do was follow his lead and confound every body with my Wiki knowledge.

[JeffG]

I confess I didn't read the whole of this thread, so missed the explanation of the term

My brain tends to shut down when people start talking (a) cars (b ) politics or (c ) sport.

And of course I check something I don't know on the internet first, rather than getting ripped apart for asking and being pointed to Google!

[motormad]

I didn't google anything in my headlight discussions, it is basic engineering. Poor MM still doesn't understand the concept so, whilst this thread was entertaining, he knows best so I must bow to his superior knowledge. Pity I wasted all that time in my formative years. All I needed to do was follow his lead and confound every body with my Wiki knowledge.

I didn't google anything either.

Poor Exhausted still doesn't understand the concept so, while it was entertaining, he knows best so I must bow to his superior knowledge. Pity I wasted all that time in my formative years [If only you'd spent some of it reading the highway code]. All I needed to do was follow everyone my Wiki knowledge.

[Exhausted]

I didn't google anything either.

Poor Exhausted still doesn't understand the concept so, while it was entertaining, he knows best so I must bow to his superior knowledge. Pity I wasted all that time in my formative years [If only you'd spent some of it reading the highway code]. All I needed to do was follow everyone my Wiki knowledge.

Sorry, I forgot about your work experience at the Car Clinic. Bet that made you handy with a broom.

[motormad]

And making cups of Teas!

[Biker1]

I didn't google anything in my headlight discussions, it is basic engineering. Poor MM still doesn't understand the concept so, whilst this thread was entertaining, he knows best so I must bow to his superior knowledge. Pity I wasted all that time in my formative years. All I needed to do was follow his lead and confound every body with my Wiki knowledge.

You are quire right in your explanation that you do not get something for nothing energy wise and that, of course, if you have your headlights on, then the energy has to be provided by the engine and therefore some consumption of fuel.
My argument is that, if you have to worry about this small amount of extra fuel consumption and sacrifice safety because of this, then maybe you should not be driving a vehicle in the first place?
All motorcycles now have the headlights on permanently (when the engine is running) for obvious reasons and I tend not to worry about the cost of having this feature!
If you need to concern yourself about the cost of having headlights on when safety reasons require it then perhaps you need to consider the following money saving tips:-
Do not buy a car with air con.
Careful with the use of that HRW maybe a good scrape will save you money.
In car entertainment is detrimental to fuel consumption.
Try, as many do, to not indicate.
Only use those wipers if visibility dictates that you REALLY have to. (Also saves on the cost of wiper blades.)
Fog lights make it safer in fog but think of the cost.
Try not to brake as this uses the brake lights.
Ditto for reversing.
Don't flash headlights or use the horn as this can rapidly empty your wallet.
Try to bump start as this will save valuable energy by not using the starter motor.
etc................

[Andy Capp]

I suspect the recent debate hasn't been about saving fuel, but more about seeing who can pi$$ the highest!

[Exhausted]

I suspect the recent debate hasn't been about saving fuel, but more about seeing who can pi$$ the highest!

Yeah, you're right. I really wasn't concerned about fuel use either but it was a tongue in cheek reply to you.
Sidelights save using battery power and help in areas with no street lamps.
Me, I just drive into Sainsbury when the gauge shows nearly empty and drive away when the tank is full. I need fuel to make my car go so I don't lose too much sleep over the price per litre nor, my Miles per litre either. As I use the middle lane of the motorway, my driving economy is quite good as I don't have to keep slowing down and then accelerating back up changing lanes. Now that MM has educated me I feel I can run my air conditioning all the time as well as it doesn't use any energy, it comes from the alternator at 14.5 volts.

[Biker1]

Yeah, you're right. I really wasn't concerned about fuel use either but it was a tongue in cheek reply to you.
Sidelights save using battery power and help in areas with no street lamps.
Me, I just drive into Sainsbury when the gauge shows nearly empty and drive away when the tank is full. I need fuel to make my car go so I don't lose too much sleep over the price per litre nor, my Miles per litre either. As I use the middle lane of the motorway, my driving economy is quite good as I don't have to keep slowing down and then accelerating back up changing lanes. Now that MM has educated me I feel I can run my air conditioning all the time as well as it doesn't use any energy, it comes from the alternator at 14.5 volts.

Don't fill your tank, it uses more fuel to carry it around!
Only add small amounts at a time for economy!

[Exhausted]

Don't fill your tank, it uses more fuel to carry it around!
Only add small amounts at a time for economy!

Oh my God, I didn't think about that. My tank takes about 80 quids worth. Now I won't sleep tonight.

[HJD]

All new motorcycles now have the headlights on permanently (when the engine is running) for obvious reasons and I tend not to worry about the cost of having this feature!

I think you missed a word out there biker. My bike being a few years old still has a switch to turn them on / off although I do tend to ride with them on. Going back to the original posting about duff headlights, If any one ( & I think there are a couple ex motorcyclists who frequent the forum as well ) has ever had the following experience it is quite a good laxative I can assure you. Imagine a dark night & an unlit road, you are traveling on your bike at a legal speed & come up behind a slower moving car. Coming toward you is a single headlight, ah another bike you think plenty of room to overtake ! Sh** it's a van with only his nearside headlight working !!!!!! Somehow I just managed to miss it but the thought of it still makes me shiver !!

[motormad]

I suspect the recent debate hasn't been about saving fuel, but more about seeing who can pi$$ the highest!

In Year 3 or 4 I pissed over a Cubicle onto some kid.
True story.

[Biker1]

I think you missed a word out there biker. My bike being a few years old still has a switch to turn them on / off

Quite right, but my oldest is 2005 and I can't turn the lights off on that.
It is some time since I owned a bike with an on/off light switch.

[HJD]

My bike being a few years old still has a switch to turn them on / off

Being a few years I meant 24.

[Biker1]

Being a few years I meant 24.

Nice.
What you got?