The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas - Jalopnik Comments

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

TPSreports — Wed, 26 Jul 2006 12:18:59 EDT

People drive their cars 50% during the day and 50% during the night? Where? Above the arctic circle?

TPSreports

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

RocketScientist — Wed, 26 Jul 2006 11:45:15 EDT

Let's not forget the gas saving tip of proper tire inflation and rotation.

Speed limit reduction only makes a big difference if your car isn't geared for higher speed highway driving.

Watch the tach. The lower it is, the less gas you're using.

RocketScientist

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

Jim K — Wed, 26 Jul 2006 09:40:28 EDT

I have disabled the DRL on each and every car I have that came with them; I find (as a motorcycle rider) they de-sensitize people to headlights, which is the ONLY thing that keeps motorcyclists alive sometimes, AND they have glare, AND they are completely useless in broad daylight in the lower latitudes.

If I wanted my headlights on, I would switch them on. I am sickened by the creep of Big Nannyism from our Gubment and industry.

Jim K

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

DeeJayQueue — Wed, 26 Jul 2006 09:21:29 EDT

the alternator has 2 major functions
-keep the battery charged
-generate power to the spark plugs

once the battery is charged that power gets turned into heat. the torque load on an alternator doesn't change regardless of the electrical draw on the car. Therefore if you're not powering something while you're driving the extra energy is wasted.

With an a/c compressor the torque load does change when it's activated, so it draws more power from the engine.

This article basically debunked itself. How many times can you say "lets assume" before there are just no solid facts from which to form an hypothesis?

Still though, I'd like to see mythbusters do a segment like the "tailgate up or down" myth only do headlights on or off... where they drive out an entire tank of gas in 2 identical trucks and see if one runs out first.

DeeJayQueue

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

buttersideup — Wed, 26 Jul 2006 08:57:33 EDT

Adam...

My Viggen showed an average of about 25 MPH over three years of typical commuting. And I dont drive slow...

blalor...

Last I heard energy is never free, output can't be more than input and alternators don't store energy.

buttersideup

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

Frank — Wed, 26 Jul 2006 05:08:37 EDT

Headlight fluid is much cheaper than gas.

Frank

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

Mike the Dog — Wed, 26 Jul 2006 04:42:08 EDT

No, Adam, the logic behind turning off the A/C is that when the A/C is running, the clutch on the A/C compressor is engaged, turning said compressor with engine power via the belt drive system. This compressor requires a significant amount of power to do its job (The number 5 HP jumps to mind, but I'm not sure if it is correct.) The fan that pushes the air itself uses slightly more juice than the headlights, and is subject to the argument above. Does anybody here know for sure how much HP an A/C compressor requires to do its job?

Mike the Dog

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

Adam — Wed, 26 Jul 2006 02:11:51 EDT

Well, I know that if you don't put a load on an electric generator (alternator, whatever) it has significantly lower resistance than if there is a load. If the battery is fully charged, I would imagine this lack of a load on the generator would cause it to spin much more easily. Isn't this the logic behind turning off the A/C?

Adam

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

joedoe — Tue, 25 Jul 2006 22:56:32 EDT

What's next? We all turn down our stereos by three notches and save even more gas? Followed by the A/C off below 75 degrees campaign... followed up by... you get the point. It'd be different if the calculation was correct, but I agree with balor. There is virtually no savings. I'd be curious to know how many accidents have been avoided because of day time running lights. Imagine how much gas is saved by not having those accidents, destroyed cars etc (not to mention burials... hearses get AWFUL gas mileage I tell you). Calculate that! HA.

If anyone actually wanted an easy way to save a substantial amount of gas, we'd drive the speed limit. I know I sure don't.

joedoe

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

blalor — Tue, 25 Jul 2006 22:28:19 EDT

Ok, that's assuming there's additional load on the alternator required to power the DRLs. I don't believe that's the case; I think a healthy alternator is producing *more* electricity than is used by electric system of the car. So using your DRLs or turning on your headlights or crankin' the Husker DÃ¼ up to 11 is just using excess juice that would otherwise be turned into heat.

blalor

The Day-Walker Woodchuck: How Much Gas Would A Headlight Use If A Headight Did Use Gas

Adam — Tue, 25 Jul 2006 21:38:38 EDT

30mph? Seems a bit low for an average.

Adam