Lumen is the measurement of a light being produced by the source & received by a surface. Just another way of measuring wattage or optical power. A lumen is the metric version of candle power, which was the old school 1 candle illuminating a 1 foot square, 1 foot away. 1 Lumen is the metric version of 1 candle 1 foot away from a 1 foot square ( the whole square, not just the center ).

The useful test is to use a light meter to measure the light received at a given distance ( for the application, say fog lamps ), to compare light sources, comparing the optical power of something 12" from the bulb ( and the bulb alone ) is not useful in all applications.

A 60 W H4 bulb is about 1895 lumen output, so if you use an even distribution, the 400 lumen LED light output ( not taking into account reflector design, just the bulb itself ) is about 21% of the light output of the 60W H4 bulb when measured 1 foot away from the source.

This would make the LED bulb ( marketing number wise ) the same as a 12.6 W bulb.
This is where the "equivalent to xx watt bulb" comes from with LED bulbs ( house hold bulbs, etc )
The LED is not a 12W LED ( or the total of the LEDs is does not equal 12 W ), but the measured output of the total LEDs has a lumen output equal to a 12 W standard bulb, when measured at a distance of 12".

Usually lumen is a term used with flashlights, as the output of the light ( focused in a given area ) is what matters, not how big the bulb is ( wattage ) and what is being used to drive the light source ( 2 AAA batteries or 2 CR123 batteries ).

To give an example ( of LED designed reflector designed units ), this is a 500 lumen flashlight, using 3 LEDs


This is a single LED flashlight, with 160 lumen.


Do either of these have a useful light at 20' ? Good question, but the unit of measurement marketing only cares about the light output at 12", which means if the reflector is designed to work best at 12", it can claim 500 lumen, but at 20', the light might be less than a zippo lighter.

Same applies to LEDs in reflectors made for standard bulbs, the reflector for the fog lamps is made for the true radiance circle of the standard bulb, where the LED bulb above looks to have the same radiance circle, but it does not, it is trying to emulate it.

This is why the LED tail lights look cool up close, but at distance the delta brake lamp to parking lamp is barely noticeable ( diminished lumen at 40' due to scatter from the light design and wavelength ).

Any LED light source is designed with the LEDs and the reflector, to have the amount of usable light at the required distance for the application.

LED tail lamps that are DOT approved are complete units, not just a bulb in a standard housing made for incandescent bulb.

Would be curious to see what a light meter has for the output with these installed, when measured at 30' - 40' - 50', compared to a standard 9145 bulb.

If lumen output is the only thing you are going to use as the decision, might as well get 2 of those Cheap LED flashlights and install them where the fog lamps are, they have 25% more lumen as the 9145 LED bulbs, and you can buy a whole bunch for USD$ 70.00.

 

Good read

 

I will get pics up asap, I just installed them yesterday. But to answer your question as far as I know they run much cooler and draw significantly less current, so your harnesses should be just fine.

As far as useful light, when I pulled into my driveway I turned off the headlights and just left the fogs on. From about 40 feet away they lit up the front of my 2 story house! I'm quite impressed by just how much light these guys put out.

I still have the factory halogens in my headlights, so they don't match the pure white fogs. The new fogs definitely look coolest during twilight times when i use the parking lights and fogs. I got several looks, even one from an Audi with led headlights!

 

Were they giving you the stink-eye or one finger salute because of the glare?

 

Sounds like something is already wrong....... Fog lamps should not light that far up something, they have a low cut off pattern.

 

Funny guy. I had hids in my old truck and took them out because no matter how far a aimed them down they still blinded other drivers. These new fogs aren't an issue.

As far as shining on the house, the truck was facing uphill on the lip of the driveway, the factory fogs did the same thing from the angle.

 

Still have the stock fog bulbs? Swapping is easy, try swapping the stocks back in for a pic, then put the LEDs in, and get before and after shots of a garage door or whatever your truck illuminates in your driveway. How much were the bulbs? Could you also get a shot of them laying beside the OEM bulbs?

 

That is one heck of a lip to get a light with a cut off up 2 stories on a house, what is it a 20* to 22.5 approach angle ?

Story house ~ 20' to the gutters, the other leg of the triangle is 40', makes the hypotenuse 43.8' long, which if the house to driveway is 90*, the cut off would fall about 18' and illuminating below that, making the truck on a 22.5* angle, and the cut off falling at 18' high, with an angle of 67.5*.

BTW, this means you rear of the truck on a 6.5' bed is on the ground, and on a 8' bed just above the ground, getting ready to bottom out.

Think you are including reflectance with your light comparison.

 

calm down there, Einstein

my 8 DRL LEDs in a pure pitch-black environment will light up my parents driveway a good 20' in front of the truck. Not enough to drive by, but enough to sneak in/out without HIDs lighing up the whole field

 

If you are talking about the 9145 LED bulb, this is a good example of how they are not putting out the same amount of lumen as a standard 9145 bulb, if they only light up less than the length of the truck.

The site listed above calls the 9145 LED bulbs DRL/fog, this is why I ask if you are talking about the same thing as I am.

 

If they're the ones he wanted to get earlier in the thread, 70 or 80 bucks (can't remember which ones.)

FWIW, when I had my old fogs, the glare guard in my drivers side fog had melted off (probably from running the 9005s in there). Every time I turned them on, I, too, could light up houses. Was the reason I never really ran them. Either way, I've since replaced them.

 

Not those windmill/spider looking ones, frankly i do not see how they could fit in a housing, and they would look hideous inside the lens haha. These were the ones I was more interested in knowing about

 

Yea, those, 69.99

http://www.v-leds.com/Exterior-LED/D...-p7652845.html

A bit pricey if you ask me. But as long as the OP is happy...

As for the spider things, I think the "legs" are on hinges, so you "close" them to fit in the hole, then they spread once in.

 

$70 for LEDs, for $100 for HIDs, I think i'd save the extra $30 for actual output light HIDs with nicer looking bulbs, but if they get me in trouble with johnny law, i'd sell them and buy them ugly LEDs hoping they would be less blinding.

 

Hids usually run about $50 nowadays