Diode Dynamics SL1 Review

Diode Dynamics finally released their first LED low beam replacement bulb. I was sort of surprised it took them this long to come out with a bulb. I asked their representative about the delayed entry into the market and his answer quite surprised me. He said that unlike other LED bulbs on the market theirs is manufactured here in the USA and is also designed to work not only in projector style housings but also in reflector style housings. It's designed to have a near perfectly matched filament location so that even in reflector housings you won't get the glare common to other brands all while preserving the focus and hotspots. (DISCLAIMER: I couldn't remember exactly what the rep said so I'm copying some stuff off the Diode website, but whatever he said was somewhat along those lines anyway)

The first thing I noticed when unboxing the bulbs was the low profile heat sink. Apparently this is a brand new design that increases the cooling efficiency all while keeping it low profile for those vehicles that have dust caps behind the low beam. I can first hand tell you how great this is. After buying a set for my Tacoma, I was so impressed that i bought a second set for my wife's 2016 Kia Optima. Her car has those dust caps and I guarantee there is no other LED bulb out on the market that puts out this much light and you can still close the dust caps behind it.



The only downside that I have noticed thus far is that these bulbs do not have built in resistors. So if you install these on any vehicle (Like my wife's Kia) that has a nanny sensor to tell the driver of a burnt out headlight, you may also need to buy Diode's anti-flicker module. It's a simple inline plug n play module to trick the car into thinking everything is okay. That retails at $30 for a pair so it's really not a big deal.

Below are some comparison pictures I took and for the record, Each comparison picture was taken with identical camera settings like Aperature, shutter speed, and ISO. So they are fair comparison pictures. While I used photoshop to merge the pictures and added text, I did not mess with any contrast, color, or brightness settings.




OEM


SL1


SL1 with XML2 fog lights

 

I wonder what these look like in a reflector type housing...like a second gen??

 

Supposedly they work very well in a reflector housing. Focusing the light on the road instead of into the eyes of oncoming traffic. However we'll never know until someone in a 2nd gen bites the bullet

 

Fortunately they do not make an H4, according to their website. Regardless of the ability to control glare, LED bulb designs like those pictured fail to illuminate the most critical portion of the reflector/projector responsible for distance illumination. Meaning even in a projector housing that will control glare the distance illumination will suffer. This is why LEDs are always said to lack 'throw'. While the 3rd Gens can run these kinds of LEDs in their projector housing they would not be recommended for an 2nd gen reflector.

 

bummer. thx

 

Id like to see compared to an HID and the distance they can illuminate.

Bottom photo looks like there are patches of dark area

 

The SL1 are all single filament bulbs. They are now working on producing the SL2 which will be all your dual filament bulbs like H4. So give it a couple months and I'm sure the H4 will be out. @crashnburn80 not sure if you read my post but the filament in the SL1 was designed to match the length of the filament of your regular incandescent bulbs so not sure where your getting this information about how "LED bulb desings like those pictured fail t illuminate the most critical portion of the reflector responsible for distance." Kind of feel like your comparing new engineering with cheap Chinese crap

 

I don't have any HIDs but if I did I'd take comparison pictures. I think what your seeing in the bottom picture is a gap between the fog lights and low beams. That is pretty normal and isn't visible from the driver's seat.

 

I’m not debating product quality, but the basic LED retrofit design is flawed. On all retrofit LEDs. A halogen or HID bulb is a true bulb that has omni-directional illumination, meaning the entire reflector/projector housing is lit uniformly as light is emitted in all directions from the bulb. The current LED headlight retrofit design ‘bulb’ uses directional LEDs on the sides of a thick rod. These LEDs point to the sides of the reflector/projector and being directional, they do not light the housing uniformly. Most importantly they do not point to the top rear of the reflector/projector (there is a large rod in the way) and this leads to dark spots in that location, which is the location responsible for down field illumination, meaning distance illumination or “throw” will suffer. If you do this in a reflector headlight you can see the dark spot in the headlight assembly above the LED bulb, compared to stock which is fully illuminated. So while you can position the LEDs in the same spot as a halogen filament the design is still significantly flawed. You cannot point a light bulb, but you can point an LED diode, and there is the problem. A halogen reflector or projector needs an omni-directional light source like it was designed for to uniformly light the reflector and LEDs are not an omni-directional light source. Hence OEM led headlights on new cars look nothing like halogen headlights.

And props for trying to control all the variables with an manual set SLR in the photos.

 

Yeah I read it...that's why I was excited...I'll keep an eye out for the dual filament/h4

 

Your logic is sound. I guess we really won't know until someone puts them in a reflector housing and takes comparison pics

 

Nice to see an LED manufacture actually making them in the USA though.

 

i've been eyeing these ever since they were announced last year. from the looks of it, they seem great. but i'm still debating between these and HID.

 

I know the struggle. I ended up going with these since they are plug n play. With the HIDs I was going to have to wire up a relay and run wiring. These are as simple as unplugging the old bulb and plugging these in. It was a 10 minute install

 

yeah i like the simplicity. but i also want the output of HID. gotta give something up....

 

Yup. The HID definitely puts out more light. For me personally the SL1 is plenty even with having a tinted windshield. If I need anymore I'm usually in an area where I can turn on my high beams or use my off road lights

I live in the suburbs of St. Louis where street lights illuminate the road really well. If I lived in a more rural area I could definitely understand wanting HIDs and having as much light as possible

 

how does it perform in rain, snow, icy conditions, etc.? i know there is a thread where the LEDs were did not dissipate enough heat to clear the headlights when driving in those conditions. here in WI, we get our fair share of it and although its very rare it would happen, i wouldn't want it to during a long drive.

 

Yeah I know the Candians have to stay away from LED because the heatsinks on the bulbs draw the heat to the rear of the bulb instead of forward to melt the snow. So yeah if you live in an area where you get an overwhelming amount of snow. LED may not be the best option. Here in St. Louis it's just cold, we don't get a lot of snow.

 

The wife's 17 Corolla came with factory LED, and they are the most amazing headlights i have ever driven with. Bright clear white light, evenly covering everywhere you need. I paid almost twice as much for my Tacoma, and the fact that they still only come with halogen blows my mind. So disappointed when I drive it at night. These look like a good option, thanks for the info.

 

Are there any discount code for TW members?