Lead SA - driving with your lights on - why?

[Rouxenator]

On long distance trips I might switch on my lights since the distances at which you need to be visible are much larger than in town. However I am complete against any for of fog light abuse and bright blinding other drivers.

Your best bet is always to get a car that is visible (not black) and does not blend in with the rest of the traffic. I got myself a teal gay blue Corsa (as described by VAG drivers) and I believe its very visible for other road users.

Have to agree with Fazda on the pedestrians part - especially here in Stellenbosch they just walk anywhere on the road they like.

 

[markings]

AN aspect which I believ we don't consider. I have the impression that bright things appear to be closer than dark things. Using the lights during daytime is therefore safer as a risk taker may hold back risky maneouvers.

 

[Claymore]

Then their lights aren't working. You can't switch off a bike's headlight/s

That's a hell of a lot of bikes with faulty lights then. Is it the case with all manufacturers?

 

[Claymore]

An alternator / generator is driven my a car's engine to keep the battery charged. And any load (e.g. anything that consumes the power it generates - in this case the car headlights) will create more load on the alternator, which translates on the car engine having to work just that little bit harder to keep it outputting the same voltage, so the car will use more (a tiny amount) fuel.
But .... my comment in my previous post is not to be taken too seriously anyway

What generates the additional resistance in the alternator? I mean, the only friction is on the shaft bearings and brushes, and the alternator runs at a constant fraction of the engine speed.

 

[UnUnOctium]

What generates the additional resistance in the alternator? I mean, the only friction is on the shaft bearings and brushes, and the alternator runs at a constant fraction of the engine speed.

Decrease in resistance of the system translates to the rotor's magnets providing more resistance per turn on the drive shaft, i.e. the engine must use more power to maintain the same rotational speed of the alternator. Easy way to prove this is to let your car idle (after the choke is off) and then switch on the lights, you'll hear the engine drop RPM slightly.

 

[atomcrusher]

What generates the additional resistance in the alternator? I mean, the only friction is on the shaft bearings and brushes, and the alternator runs at a constant fraction of the engine speed.

I don't profess to be an expert on the load vs. fuel consumed, i.e. higher the load = more fuel consumption. But, and as an example, I am in the process of installing a 500kva genset at my factory, to minimise the costs I incur when our incompetent City Power folk decide to not provide what I pay for ...

The Genset being installed is powered by a Cummins diesel engine, which turns the alternator, to generate (expensive) power so I can continue to provide employment, by staying in business. The Genset manufacturing specs give fuel used vs. differing loads on the Genset (i.e. dependant on what and how many machines I run at any one time). Example fuel consumption figures are given thus:

@ 100% load = 103 L/hour fuel used
@ 75% load = 79 L/hour
@ 50% load = 55 L/hour
@ 25% load = 30 L/hour

So I deduce that the more load placed on the alternator = more fuel consumed.

I assume the additional load on the alternator (which translates to additional load on the engine, which drives the alternator, and which consumes fuel) is caused by the alternator being forced to output a higher voltage and/or current, to compensate for the increase drain (load) caused by lights-on.

Back to the lights on in daylight issue ... typically the USA has a website dedicated to this ( The Association of Drivers Against Daytime Running Lights ) :erm:

... And an extract from that website:

Q. Will DRLs reduce fuel economy?

A. Yes. 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. Multiply that by 200 million vehicles in the US, and you can see why we oppose mandatory DRLs. The cost of DRLs over several years cannot possibly justify the benefits, especially the the benefits are in serious doubt. Given the increasing price of gasoline, the economic impact of DRLs will only get worse. Further, the combustion of the additional gasoline required to power the nation's DRLs will result in several billion pounds of pollutants being exhausted into the atmosphere. What makes the federal government's position on DRLs seem so strange is that the Environmental Protection Agency allows GM to disconnect DRLs before testing! Why?

 

[markings]

The additional alternator load is so insignificant when compared to wind resistance when driving long distance or repeated acceleration of 1000 to 2000kg of metal when in town traffic.

 

[atomcrusher]

The additional alternator load is so insignificant when compared to wind resistance when driving long distance or repeated acceleration of 1000 to 2000kg of metal when in town traffic.

Which is why I said

the car will use more (a tiny amount) fuel

 

[dlk001]

I always drive with my lights on - obviously not bright, in order to be visible to idiots who are asleep at the wheel and pedestrians.

Certain colours also blend in with the road, and by running with your lights on you at least know that you can be seen.

+1

In surface mining, we are all required to wear reflective shirts in broad day light because research has shown this kind of visibility decreases accidents. There is little we can do to remove fatigued and tired people at work or on our roads. However, driving with lights on is a way of managing and reducing the risks.

 

[mich_m]

I drive with my lights on during the day and frankly wheneven I see other cars with their lights on I smile and think to myself "Yeah another considerate, safe driver"

 

[Claymore]

Decrease in resistance of the system translates to the rotor's magnets providing more resistance per turn on the drive shaft, i.e. the engine must use more power to maintain the same rotational speed of the alternator. Easy way to prove this is to let your car idle (after the choke is off) and then switch on the lights, you'll hear the engine drop RPM slightly.

Cool, thanks - nice explanation.

 

[Kompete]

I've been trying to navigate their website to find an article describing why driving with your lights on during the day is supposedly safer, but to no avail. Since its inception (even when it was started a few years ago in Bloem), I haven't noticed any increase in visibility - I had no issue seeing a car in broad daylight before - I'm not sure why we now require headlights. Anyone requiring headlights to see other vehicles during the day certainly shouldn't be on the road in the first place.

What I have noticed though is a vast increase in morons driving with their brights on during the day, which is just as dangerous as driving with them on with oncoming traffic at night.

I was told that it makes overtaking safer because you can now see headlights in your rearview mirror. Well fark me sideways and call me Miss Piggy - before the headlights I would have seen the entire vehicle - it's not like the beams extend anywhere during the day like they do in the evening.

I really do not understand this campaign. Hopefully someone can shed some logical light here for me, so to speak...

OK i didnt go thru the whole thread so apologies if someone already explained this to you.

Driving with your lights on during the day 'increases' your visibility to other drivers...fact. In some countries its compulsory to do so and in some e.g. opencast mining operations its compulsory.

Obviously this does not mean you should have your brights on. And the argument that bikers are then less visible, is a red herring...bikes are not less visible, other cars are now just as visible as a bike. It would be like saying "bikers lives are more valuable than car drivers"

Whether 702 is trying to get brownie points from this campaign or not is completely irrelevant...'dont cut off your nose to spite your face'

 

[Grimspoon]

Driving with your lights on uses fuel? :wtf:

Edit: If thats the case with the petrol price as it is, I am going even drive at night without my lights on

 

[SmartKit]

http://www.arrivealive.co.za/pages.aspx?i=1819

 

[Fazda]

A study in America showed that it would cost $7.62 million daily in fuel if everyone in the US drives with their lights on in daytime. Now imagine if the world all drive with their lights on. Cars lights can take anything from 10-20 amps of a cars alternator. All DRL’s should be led based, as a set of high power ones would only consume in the milliamp range.
For more on the advantages and the disadvantages go to www.celgo.co.za.
Safety should not be at the cost of the environment

This just goes to prove what utter bollocks you can pick up on the net!

There are so many factors influencing fuel consumption that a statement like that simply makes me bloody angry. Seeing as it's gombault's first post, I will go easy on him, but for Pete's sake think something through before blindly quoting it!

 

[HapticSimian]

Driving with your lights on uses fuel? :wtf:

'course it does. Lights require energy, and the only source of energy your car's carrying along is fuel. It's a minute amount, but having your lights on will necessarily use a bit, just like the aircon does.

 

[Fazda]

'course it does. Lights require energy, and the only source of energy your car's carrying along is fuel. It's a minute amount, but having your lights on will necessarily use a bit, just like the aircon does.

I agree with you, however, to try and blame lights for chewing up nearly $8million in fuel whilst driving in choked up conditions in gas guzzling Yank tanks is taking a rather skewed look at the problem whilst trying to argue their point.

Americans usually find some excuse not to do something that infringes on their right to absolute freedom of choice. If you say "Drive with your lights on" they will find a thousand reasons why you should not...

 

[HapticSimian]

I agree with you, however, to try and blame lights for chewing up nearly $8million in fuel whilst driving in choked up conditions in gas guzzling Yank tanks is taking a rather skewed look at the problem whilst trying to argue their point.

Americans usually find some excuse not to do something that infringes on their right to absolute freedom of choice. If you say "Drive with your lights on" they will find a thousand reasons why you should not...

Meh. I don't much care one way or another. The amount used or saved would be so tiny that a daily single spirited pull-off is likely to use more in any event. That being said, the US has a population of 350,000,000 so it'd take $0.02 per head to arrive at seven-and-a-bit million Dollars per day. It's a big-ass country. And yes obviously not every individual drives daily - the little maths exercise is purely illustrative.

Which is all much ado about nothing as far as I'm concerned. DRLs will become standard equipment in the not-too-distant future. Until then, I'll take the added safety of flicking a switch to 'ON' with the pain of using a few cents' more fuel when I travel long distance.

 

[Fazda]

Absolutely!

As you know I always run with my lights on, and at the moment I'm getting the best consumption of all the Company vehicles, so driving like a Wally has a much more detrimental effect than lights being on.

I was once again absolutely amazed at the idiots hurtling in and out of Durban today, running literally in the dark as we have had 120 mm in the past 24 hours and these ass hats stubbornly refuse to switch lights on, and blast their way through the spray causing havoc wherever they go!

 

[dj_jyno]

at the moment I'm getting the best consumption of all the Company vehicles, so driving like a Wally has a much more detrimental effect than lights being on.

I've noticed the same in my car. Other than the normal fuel consumption fluctuations, I haven't noticed any detrimental effect due to my lights being on all the time. I've actually recorded some of my best figures over the past few months.

I was once again absolutely amazed at the idiots hurtling in and out of Durban today, running literally in the dark as we have had 120 mm in the past 24 hours and these ass hats stubbornly refuse to switch lights on, and blast their way through the spray causing havoc wherever they go!

Or the tools who think that park lights equal dipped beam and drive their silver cars like that in fog so thick you can see maximum 15 m ahead of you.