keeping lights off, how much fuel does it save really

[Arragonis]

Originally Posted by PaleMelanesian

What's your idle gph? Mine's about 0.3. Compare that to the gph of EOC = 0. Now apply that difference to half of the drive that I EOC. It makes a big difference.

Estimated 0.3 * (0.5 hour drive * 1/2 (eoc percent)) = 0.075 gallons
Regular commute = 0.14 gallons (10.5 mi / 75 mpg)
0.14 + 0.075 = 0.215
10.5 / 0.215 = 48.8 mpg if I engine-on-coast instead. That's a 35% drop!

Idling GPH and LOD figures. Helga is a TDI, headlights are Xenons, SG2 has been calibrated for gallons ~ 4.54 litres (imperial). Let her idle for 30 secs when already warm to get the figures settled and then idled for another 30 seconds both for lights on and off to let the measures settle.

I didn't do the 30 seconds idle before just an instant on/off which didn't really show anything.

Lights off - LOD varies slightly between 20/21 - mostly 20.
GPH is 0.14-0.15, again mostly 0.14.

Lights on LOD stays at 20/21 but mostly 21.
GPH is still 0.14-0.15 againt mostly 0.15

Thats a 5-8% difference which is worth investigating further. My current tank only has 50 miles on it so I'll avoid the lights as see if it really makes a substantial difference.

[Piwoslaw]

Originally Posted by Arragonis

Thats a 5-8% difference which is worth investigating further. My current tank only has 50 miles on it so I'll avoid the lights as see if it really makes a substantial difference.

Remember that the headlights' load is proportionally larger at idle than when driving, so unless you plan to A-B-A test it, the results will probably be within tank-to-tank noise.

[dcb]

That article also mentions an "insignificant" increase of %4 more motorcycle accidents when cars use DRLs

[Phantom]

Originally Posted by Arragonis

I have no problems with DRLs, they seem much better than the alternative which is muppets in heavy rain or even at night operating in "stealth" mode.

Day Rime Running-lamps are not the same as automatic headlights, you can have one and not the other. I have found it much better to have automatic headlights than DRLs. Several cars that have DRLs reduce the power sent to the lights mostly for bulb life. My GrandPrix and a few other GM cars all you have to do is unplug a tiny box under the drivers side dashboard to disable DRL the automatic lights still function properly and if needed the lights can still be turned on manually.

Also I believe the reason that cars in the USA have DRLs is it is required in Canada so all models also sold there have it installed by default (atleast for GM).

[Arragonis]

Originally Posted by Piwoslaw

Remember that the headlights' load is proportionally larger at idle than when driving, so unless you plan to A-B-A test it, the results will probably be within tank-to-tank noise.

I may try and figure out an A-B-A test as the difference at idle was higher than I thought. Helga has a lightened flywheel compared to standard but its still heavy compared to a petrol car.

Based on this I have assumed the effort of turning it would be greater than any load - certainly using the A/C (which I have done 3x in the last 5 years) never had any effect I could detect in terms of performance. I never used it long enough to determine an effect on FE.

Originally Posted by Phantom

Day Rime Running-lamps are not the same as automatic headlights, you can have one and not the other.

I deliberately turn mine on, I don't have DRLs or auto lights, just a switch by the wheel which I use to turn on the dipped lights. I started doing this when I had a FIAT which allowed it and the number of people who would pull out, do a double-take and choose not to was quite amazing, so I have run with headlights ever since. Around the same time I worked with a biker (as in MC) who said he always ran with lights otherwise he seemed to be invisible.

Originally Posted by dcb

That article also mentions an "insignificant" increase of %4 more motorcycle accidents when cars use DRLs

Every MC I see these days uses lights too, see my comment above.

I agree though, if everything stands out then nothing does.

[dcb]

Originally Posted by Arragonis

...
Every MC I see these days uses lights too.

It is the law here to leave your motorcycle light on, and it apparently made bikes 4% safer before cars started turning their lights on during broad daylight too.

Originally Posted by Arragonis

I agree though, if everything stands out then nothing does.

Yes, and nobody is trying to make pedestrians stand out or have pedestrians/bicyclers compete with 100+amp alternators on cars, so bikes and pedestrians lose when cars all decide to use DRLs, not your problem I guess.

[dcb]

not gonna fly, driving is a privilege, walking is a right.

[Thymeclock]

Originally Posted by Old Tele man

...hey, the states could "license" WALKING and make more $$$, then, later, "license" BREATHING too (wink,wink)!!!

...besides, this isn't England, where people have the "right" to walk across property not belonging to them (look it up).

...it's America, where "rights" are apportioned by your income (and, thus, ability to hire more costly lawyers)!

Indeed. The State will determine what your "rights" are.

Once anything requires a license from the State, it then becomes a "privilege".

Get that mandatory, tax-generating, air flow meter back on your nose, buster, before the "Air Police" (a task force of the EPA?) get here!

[dcb]

Originally Posted by Thymeclock

...
Get that mandatory, tax-generating, air flow meter back on your nose, buster, before the "Air Police" (a task force of the EPA?) get here!

Lol, with appropriate penalties for mouth breathers. I hear they will jump start the program and initial equipment investment with seed money from all the traffic enforcement cameras.

[Arragonis]

Originally Posted by Old Tele man

...that's IT...another truly Great Idea!

...make all pedestrians wear 1,000 Watt LED lamps or they can't use the pedestrian crosswalks!

...and, DRL's when walking on the sidewalks!

Might help prevent Pavement Rage.

Originally Posted by Old Tele man

...besides, this isn't England, where people have the "right" to walk across property not belonging to them (look it up).

This is a little over simplifying it I feel.

In "Britain" there are two laws here - implied consent and the right to roam. Implied consent means that people carrying out their peaceful business are allowed to enter my property - so the postman can deliver stuff through the letterbox, UPS can knock on the door etc. As a property owner I can withdraw consent to any specific person or legal entity at any time. If I secue my property than nobody is allowed to break in.

The right to roam governs access by ramblers to open land including farmland. This is given on the basis that those doing the roaming do not cause any damage to crops, disturb animals etc.