Its a known fact that using any electrically operated device on your vehicle will reduce your gas mileage, even though it may be an un-noticeable amount. Do a web search and decide for yourself.

http://www.straightdope.com/mailbag/mradiomileage.html

 

I have PIAA XTreme White bulbs, costs $60/pair and I don't want to replace those every year, so I'll remove my DRL.

Thanks,

 

I guess it considers the extra resistance from the alternator a hinderance to fuel economy. The more current you use, the more force it takes to turn the alternator. Similar to what happens when your A/C compressor kicks on but its constant. The extra fuel used is marginal, maybe on par with a 5 MPH headwind.

Cars with DRLs get lower insurance rates. If your insurer finds out they are disabled they may want to charge you more.

I turn on my headlights on 2 lane highways during the day to be as visible as possible. Its the same reason I choose bright yellow to paint my front bumper. Driving a brown truck simetimes makes you less visible.

 

I hope you mean while you are parked. Do this while you are driving and say goodbye to your rear brakes.

 

LOL, from now on I'll drive without listening to any music in my 4Runner and I will never use my turn signal either!

 

Andrey,
Don't know if you even notice it but the more acc.. you run the more load you put on your engine reducing milage. Nextime you are driving along at a steady pace switch on your climate control fan up to full speed w/o AC on. You can feel a noticable drag on your motor, why is this so?? it's only an electric motor in your heater fan. The fan motor at high speed is pulling a significant amount of amps which causes a system drain and makes the alt. work harder. Your radio (stock) and turn signals do not pull enough amps to effect your milage. High amperage/wattage items such as Headlights, heater fans, high power stereo amps do effect gas milage even if it is small. Put an "amp clamp" on your battery and turn things on one at a time and watch the amps go up, and remember "Nothing in life is free" and that includes gas milage every little bit helps.

 

This all sounds good in theory, but in real life I don't notice any loss of power with either AC on or off in my 4Runner, which has 3.4L engine. I do notice a difference when I tow a trailer, but with fan on or off? Seriously, what kind of screw engine I need to have which will start loosing power when I turn on DRL?

There are many many other things in life which affect gas mileage, such as frequent stops and go, using accelerator pedal too often, etc... But the difference with accessories is really probably 0.01-0.03%. And personally, I would rather enjoy my ride with nice music, cool interior and pleasant looks when saving 0.01% on gas. Heck, if I can afford $35K vehicle, I don't believe $0.05 is going to put a hole in my wallet

-- Andrey

 

Hmmm...I lose about 10-15% of my power with the AC on. Weird.

 

I think you guys are getting jumbled up on your definition of "power".

The 10-15% loss is in terms of horsepower when the A/C compressor is engaged. I think other folks here are talking about electrical power because of the additional load on the alternator with the cabin fan motor kicked up.

fwiw, I too lose power with the A/C engaged, I have in all the cars I've owned. That compressor pump puts a real drag on an engine.

 

I heard a crazy statistic like if all cars had DRL's that there would be 14,000,000 more gallons of gas used every hear or some insane number like that... don't know how true it is.

 

If anybody's interested, I did a quick, rough calculation to figure out how much DRL cost per year.

190hp=141700watts
DRL @20watts each=40watts (guess)

40w/141700w=0.00028 so DRL use 0.028% of the engines power.

At $30 to fill up a tank-- $30x0.00028=$0.008
Fill up an average of once per week $0.008x52weeks=$0.44

44 cents for you 3rd gens. This does not take into account losses in the alternator and other electrical losses.

Spread out across the country this could be significant.

So everybody is correct, DRL lower mileage, but not significantly to the individual.

Steve

 

Well, the weight of my airbags take some performance, but I am not about to sacrifice that safety feature.






(Just being the devils advocate here)

 

Yup, me too. Like I said, everybody is correct.

 

Well... if you don't want to do any wire-snipping, there IS a simple alternative. I noticed one day that if your e-brake is pulled up even one click BEFORE you start the engine, the DRL's don't come on! One click doesn't physically engage the emergency brakes on on my 4Runner, so there's no rubbing, but electronically, the computer thinks they are engaged, and it's good if you want to sneak up on someone, with the engine off anyways of course. With the key in and the engine on, all you have to do is let off the e-brake and voila! One come the lights! Just make sure your key is in position 1 (right after inserting it) or not in the ignition at all when you pull your e-brake 1 click, and if you do rub don't keep this doing this. You can let it off at any time, engine on or off, key in or out. I guess it's the best of both worlds.

Zach

 

Thats the way it is in my dads Chevy pick up. We sit in line at a public duck hunting place, and were blinding all the guys in front of us trying to sleep when we would turn on the rig to warm up the cab till we found that out a couple years ago.

I personally would use that feature than mess with the wiring of a new rig. I drive an 87 Runner so its all fair game.

Just my .02

 

What you can do is also wire in a toggle.
Spilce it inline with that wire.
Put the switch up near you on the dash or underneath.

That way when you want the DRLs, no problemo

 

wouldnt this just be the same as turning your headlights on and off?

 

Nope, that will let you let the DRLs work like they are suppose to.
Flip the switch, and no DRLs on in the day light.

 

DRLs are a bit dimmer than regular lights, and much less so than the brights. I have aftermarket headlights installed (bright!), so I put my light switch in the parking light position at night. It seems like I have three degrees of lights hehe (DRLs, normal, brights). About earlier posts...the alternator is never more "difficult" to turn for the engine, whatever the load. It puts out what it puts out. The A/C compressor is a load on the motor when the compressor clutch is engaged, not the fan for the interior.

 

Actually, the alternator does increase the load on the engine when the electrical system needs more energy. This is the basis of regenerative braking on hybrid cars, electric cars and R/C cars. When the electric motor turns into a generator, it applies an opposing torque to the wheels because it converts kinetic energy into electrical energy.

It's like when you put a sudden electrical load on a generator, the engine slows down for a second before it can compensate. Why do you think it takes such a huge energy source like nuclear power or a hydroelectric dam to turn the generators? If the load is just there then you can just have a guy on a bicycle turn the generators.

Another example is when I use my signals on my corolla. Whenever I turn them on, my engine RPMs drop slightly everytime they blink.

Steve