Another Senseless Death!

[STEVE G]

Theoretically they are right, you would save a tiny amount of petrol if you survived long enough!
The saving would have to be miniscule; if I could remember the math's I would work it out just to see how economical this suicidal practice is.

[HHTel]

Surely not. The lights are powered from the battery aren't they. That in turn is charged by the alternator which is running all the time the engine is on. Maybe that's an oversimplification. Would love to hear the argument for saving petrol.

[lomuamart]

I always thought that the logic here was to save on the battery as well.

[Terry]

HHTel

Lights on Cars and Motorcycles are powered by the alternator - assuming the machine is running. The amount of energy 'saved' must be approx = zero if at all possible to calculate.

Saving the battery is also codswallop.

In this climate batteries don't on average last more than 2 - 3 years due to the higher temperatures causing overcharging. A simple but effective way to prolong the battery life is to switch on ALL lights (Including spotlights) thus reducing incidence of overcharging.

I've tried this over the years and it works.

[buksida]

Ah yes, that amazing invention called an alternator ...

Here are a few more gems:

1) Many believe that turning off their vehicle at red lights or railway crossings will also save gas - but starting it again actually uses 5 times as much.

2) Being from a tropical climate they are used to the heat - you wouldn't think so with the amount of times you see cars and pickups left running to keep the aircon on so they can keep the inside at a temperature they're acclimatized to ... minus 5.

3) Hazard lights don't actually indicate that they're going straight ahead, its more of an indecision factor ... that can be made at any time during the manoeuvre.

4) Since vehicles here are designed for deep snow drifts and icy cold weather they need to flip the bonnets whenever they stop on long journeys so the car can cool down rapidly ... then heat up again in an instant as soon as they turn it back.

5) On motorbikes we all know that helmets are made to keep your rice warm and baskets are designed to hold your helmet ... whats the big deal?

[Terry]

Buksi - you've missed one

6) Everyone knows that the concrete in Thailand is softer - thus negating the need for crash helmets.

[HHTel]

Ok Terry, so why will everything carry on working when the alternator is not (e.g.: Broken fan belt)?

The alternator takes mechanical power from the crankshaft, transmits it via the fanbelt to turn the alternator which converts that power to electrical energy to keep the battery in good condition.

With the alternator out of action, the car will proceed merrily for some time taking power from what is stored in the battery. Lasts longer if you turn off the lights, wipers, stereo etc.

The alternator produces alternating current (AC) hence the name. This is converted via diodes into direct current (DC) and fed to the battery.

Each phase of the alternator (3 phase) can fail one by one and you may not notice until the third one fails and the battery flattens. If only one phase fails and you don't use lights or aircon etc, you may not know for some time as the charge will still be enough to maintain the charge in the battery.

I'm not a mechanic but I think the above explains things.

[STEVE G]

It's over twenty years since I sat in a classroom studying electrical theory, but basically when a generator or alternator is generating, the current flow induced in the windings has a "motor" effect that opposes the rotation of the armature.
This means that if you turn off the light on your Honda it will be slightly easier for the engine to turn the alternator due to the reduced current flow and you will save a small amount of fuel.
I don't have time to look up the mathematics to calculate the saving right now, but I would have thought it would be very small.

[STEVE G]

With a bit of thought and guessing the power of Honda Wave lights, I think you would be using less than 0.5% percent of power output at full revs.
What ever the figure, it's clear that it wouldn't be an amount worth risking your life for!

[Wanderlust]

Further to buksi's post, the other aspect of motorcycles and headlights is that more often than not the basket is right in front of the light, and is normally full of stuff (e.g. crash helmet) which blocks the light! Doh!

[Terry]

HHTel

I would agree 101% with your last posting.

However with the alternator out of action the vehicle is in a degraded mode and YES turning off the auxilliaries and lights will prevent excessive drain on the battery needed to power the machine in this case.

My reasoning was based on the assumption of the machine running in good order. Given the reliability of modern cars and bikes this is the most likely scenario. Therefore trying to save petrol and batteries as a reason for stupid driving habits is inexcusable.

Needless to say, maintenance is something that most motorcyclists here never carry out. Drive 'til it's broke - then fix, seems to be the norm.
But thats another subject

[Randy Cornhole]

If you had an enforced Mot's over here the roads would be a lot quieter. Certainly devoid of those big earth moving trucks, pumping out acrid smoke. Hmm, but then there would be no new houses? Great! bring on the MOT...

[Nereus]

With a bit of thought and guessing the power of Honda Wave lights, I think you would be using less than 0.5% percent of power output at full revs.
What ever the figure, it's clear that it wouldn't be an amount worth risking your life for!

A Honda Wave, 125 cc fuel injected model reportedly returns around 50 km / litre of fuel. The advertised horsepower is 10.1 PS (Jap wording).
In metric 746 watts = 1 hp. So for 10.1 hp we can round it off to 750 x 10, which is 7500 watts being developed at full throttle.
If the headlight draws 100 watts and the taillight 10 watts, we can round it up to 150 watts total energy required for the lights. This works out to 0.02 of the engine output! One extra blip of the throttle will use more than that!
More fuel will be wasted by poor driving methods, excessive braking, overloading with 4 bods on board, etc., even the lack of a partly streamlined helmet, than will ever be used by turning on the headlights.

In some countries it is mandatory for motorcycles to have the head light burning at ALL times, as it has been proven that they are much easier to see in the day time.

Like many things here, the facts never get in the way of simple logic.

[Terry]

A lot of thinking on this thread!

What has always bemused me here in Thailand is the Governments' total apathy and lack of enthusiasm for promoting road safety.

Book the driver of a pickup for not wearing a seat belt whilst he has his crew of 20 builders sat in the back!

Annual test for a more than three year old vehicle - check that the engine number and chasis number match the documentation!

Produce evidence that your vehicle is safe (Like MOT certificate equivalent) prior to re licensing!

yehright!

All about as practical as a nine Baht note.

And so it goes on.

Until there are sensible and punitive laws sensibly enforced the carnage will continue.

This will of course never happen.

[Randy Cornhole]

I live not far from Hua Hin school, and I can't believe it when I see school kids coming out (about 8 - 10 yrs old) riding motorbikes without helmets on, sometimes with 2 or 3 mates on board, and there are police there!! If you don't enforce basic safety rules when kids are at school, then you might as well give up...