The older members will remember the dim-dip wiring of headlights in the early eighties.
I'd several VWs where you could not drive with just the parking lights illuminated.The headlights were dimmed by a large resistor.
The scheme was pioneered in Birmingham but seemed to die a death- maybe because of the dreaded EU legislation.
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I wasna fu but just had plenty.
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I drive everywhere with my headlights on regardless of weather. During the day I use the height adjuster to dip them to their lowest setting, returning to normal height at dusk. It costs me nothing and I'm more visible.
Mr$ does the same. Before she started doing this she had a number of near misses when people pulled out in front of her in the L200. How on earth you can miss one of those bearing down on you is completely beyond me, but it happened. No repeats since she started driving with headlights on.
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I have a habit of driving cars that are either the same colour as the road or the scenery so I tend to use my headlights a lot. Like $$ I'm always careful not to dazzle other drivers, but if I'm doing so during the day it must be even worse at night and I need to get my lights seen to.
I find misaligned lights and foglights (that old chestnut) to be much more annoying - when I see another driver with dipped headlights on during the day I'm happy that they've had the presence of mind to make themselves as visible as possible.
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It costs me nothing and I'm more visible.
Not so. Headlights require power, and the power comes from petrol. So we assume your headlights are using 110W, and that you drive 12,000 miles per year, at (I'm guessing here) an average speed of 30mph.
12000 / 30 = 400 hours sat behind the wheel. Multiply by 110 gives 44kWh per year. The next bit is stolen wholesale from How Stuff Works:
First, the chemical energy of the petrol must be turned into mechanical energy by the car. This is only about 25% efficient. Next, the mechanical power needs to be converted to electical power, and this is apparently 70% efficient. Apparently, we get 10.5kWh of electricity out of a gallon of petrol (dunno if this is a UK gallon or US gallon).
So, having your headlights on means you use an extra (44 / 10.5 = 4.19) gallons of fuel each year. Change this up or down if you drive more or fewer miles. In today's climate (assuming 97p/litre) that's 15.86 litres (working US) which is just over 15 pounds.
Yes, I have nothing better to do this morning.
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Interesting - I thought it was generating anyway so you were only using excess power.
I always make sure I plug in all the mobile phones and the iPod when I'm on a trip, to take advantage of the "free" electricity".
Anyone know the real answer?
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Yes. If you place no electrical load on the engine, the alternator spins freely and draws only enough power to charge the battery. Adding more load (mobile phone, headlights etc) forces the engine to work harder.
You can tell if you sit in your car with the engine idling and turn on the rear demister. You should be able to hear the engine note change as extra load is added.
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Yes, alternators always draw some power from the engine.
Even if the alternator isn't electrically connected to anything, the engine has to provide torque to overcome friction within the alternator and pump air through the alternator via the fan behind the pulley.
As soon as you draw any electrical power from the alternator for any purpose, the engine must supply *more* mechanical power than this electrical power, because the alternator and its drive (like any real machine) is not 100% efficient.
So yes, the alternator can place a real load on the engine. This can be looked at in two complementary ways.
1) For a given driver input, during periods of high alternator demand, less power is available to propel the car.
2) To obtain the same performance during periods of high alternator demand, the driver must increase his demand of the engine - i.e. the engine must produce more power, and hence use more fuel.
So, Smokie, your ipod is not being charged for free!
Number_Cruncher
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I have seen touring car races where some drivers choose to drive with their headlights on. Are we saying that these drivers are at a power disadvantage to their non light using colleagues?
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Yes, by 0.1475 horse power. (assuming 110W)
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"So, Smokie, your ipod is not being charged for free!"
Well, it is, sort of. I get a fuel card from the company :-)
Interesting that, thanks for the explanation...
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Yes, I have nothing better to do this morning.
Well Thankfully I do. An accident will cost me a darn sight more than £15 so I'll stick with driving with my lights on, ta.
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Headlamps typically draw about 10 Amps each. This increased load on the alternator will mean the engine has to work harder to drive it, therefore requiring more fuel.
Also the voltage regulator brushes will wear more quickly and the alternator will always run hotter, so it's likely that a replacement will be required sooner.
So it's not true that it costs nothing to run with headlamps or any other electrical load permanantly on....
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It costs me nothing and I'm more visible.
But it is likely to wear out the levelling mechanism prematurely.
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L\'escargot.
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2 cycles of the levelling motors a day if I use the car both in daylight and at, which isn't that often. So let's say they get cycled around 450 times a year. Hardly an onerous task for a high torque, low rev motor to perform is it.
Good grief, people will be advocating driving barefoot to stop wear on the pedal rubber next.
Believe it or not, cars are designed to be used. And the evidence all around me suggests they keep going for a lot longer than the typical 60,000 mile change cycle we so love and adore in the UK.
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The older members will remember the dim-dip wiring of headlights in the early eighties.
Watch it! - mine has dim dip now. Sidelights on - sidelights. Start engine and headlights popup and come on dim. 1991 mx5.
Peugots had them in 1995.
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Drive an older Volvo & you have no choice; two 21 watt daylight running lights come on with ignition.
Talbot camper has two bona fide sidelights with blanked off lamphousings; the bulbs having been moved into the headlamp reflectors to give a larger area of visible light, this setup nearly caused a MOT fail, luckly I was there.
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The older members will remember the dim-dip wiring of headlights in the early eighties.
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My E reg Sierra had dip dim. I thought they were a good idea.
I drive on dip beams in poor light or on narrow lanes.
I have upgraded my side lights to W5W bulbs. These are much much whiter and brighter.
Blurb says
At last we have matching colour temperature in the zone of HID lamps.
I will always fit them in future. They give my car a greater legal visibility, without abuse, especially if a dip beam fails.
I do have a bulb failure panel on the dash but fitting a replacement dip bulb from my in boot kit requires removing the grill and lamp units and I will not be doing that job in the rain.
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Were the dim-dip headlights not an alternative to fitting beam height adjusters? I may be completely off track here, but I'm sure I recall they were used as (temporary) method of meeting the lighting regulations by some makers? The regs must have been very badly written, but that's not unusual. I had an '80's Ford with these and I'm sure I was told that's why it was.
JS
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Tom, picture a road at dusk, you have a line of cars coming towards you with dipped headlights on, except you don't, you actually have a car in front of them with just its sidelights on, but it's difficult to see it clearly with all the much brighter lights behind them.
That's why I never use sidelights in dusk.
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