improving mpg's with led taillights?

[almightybmw]

Originally Posted by VWCw

if you want to ditch your daytime running lights, they should be on a separate fuse. just pull the fuse, and no more DTLs running off your alternator.

Unfortunately not all vehicles have a simple fuse to pull for DRLs. My Pontiac has "smart" logic that disables more than just the lights. And it beeps at you. Constantly. I'd disable it (as there has been found a workaround) but I enjoy not thinking about lighting when I get in it; the lights work. I replace a $5 bulb one a year or so from burning out, which is mostly because I have the lights relayed directly to the alternator, so the voltage drop is negligible-providing greater lighting at night (I work nights, so it's important to me). And my wife enjoys the extra visibility factor when we have ugly days. The car is silver/grey, it blends far to well with flat lighting.

But you're mostly right. DRL is a simple thing to disable, and even in my case, takes 15 minutes of reading a forum post while staring at the fuse box.

[meelis11]

Originally Posted by VWCw

if you want to ditch your daytime running lights, they should be on a separate fuse. just pull the fuse, and no more DTLs running off your alternator.

But daytime running lights are required by law in some countries...

[TOOQIKK]

HIDs use less power that would solve your headlight issue and provide a much brighter light!
LEDs are fairly cheap now( have my entire dash done in Blue LEDs(left the warning lights all stock so they really pop of they go off)...all the accessory lights are done in LEDs too
if nothing else they just look cooler and are customizable!
ebay you can find some killer deals on LEDs too!

[Phantom]

Originally Posted by meelis11

But daytime running lights are required by law in some countries...

"Where are DRLs required? Laws in Canada, Denmark, Finland, Hungary, Iceland, Norway, and Sweden require vehicles to operate with lights on during the daytime. There are two types of laws. Canada's requires vehicles to be equipped with DRLs. The other type of law in effect in Denmark, Finland, Hungary, Iceland, Norway, and Sweden requires motorists to turn on their headlights if their vehicles do not have automatic DRLs. This kind of law applies to drivers only, and vehicles do not have to be specially equipped. In 1972, Finland mandated daytime running lights in winter on rural roads and a decade later made DRLs mandatory year-round. Sweden's law took effect in 1977, Norway's in 1986, Iceland's in 1988, and Denmark's in 1990. Hungary has required drivers on rural roads to operate with vehicle lights on since 1993. Canada requires DRLs for vehicles made after December 1, 1989. No U.S. state mandates DRLs, although some require drivers to operate vehicles with lights on in bad weather." Questions & Answers: Daytime Running Lights



Almightybmw your Grand Prix is easy to disable the DRL its disconnect a the plug from a little heat sink that is in the panel you see when the drivers door is open. Check out Headlamp Control for more info on it and a pic of the part.

[ShadeTreeMech]

what is the current draw of DRL, especially considering they are at a lower intensity? I somehow doubt it would make more than a 1% difference in fuel mileage, especially compared to using other ecomodder techniques.

[NeilBlanchard]

I think DRL's run at 90% of the power of the headlights, so ~45watts?

[meelis11]

Originally Posted by Phantom

"Where are DRLs required? Laws in Canada, Denmark, Finland, Hungary, Iceland, Norway, and Sweden require vehicles to operate with lights on during the daytime. There are two types of laws. Canada's requires vehicles to be equipped with DRLs. The other type of law in effect in Denmark, Finland, Hungary, Iceland, Norway, and Sweden requires motorists to turn on their headlights if their vehicles do not have automatic DRLs. This kind of law applies to drivers only, and vehicles do not have to be specially equipped. In 1972, Finland mandated daytime running lights in winter on rural roads and a decade later made DRLs mandatory year-round. Sweden's law took effect in 1977, Norway's in 1986, Iceland's in 1988, and Denmark's in 1990. Hungary has required drivers on rural roads to operate with vehicle lights on since 1993. Canada requires DRLs for vehicles made after December 1, 1989. No U.S. state mandates DRLs, although some require drivers to operate vehicles with lights on in bad weather." Questions & Answers: Daytime Running Lights

Found this from that link that Phantom posted:

NHTSA estimates that only a fraction of a mile per gallon will be lost, depending on the type of system used. General Motors estimates the cost to be about $3 per year for the average driver.

I have popup lights so it is not just about alternator load, but Cd increases when lights are open.

In Estonia we also must use headlights all time. Is the DRL same thing as low beam?