i was wondering what the difference is between a glk 350 2010 and 2012-15 headlight assembly.

 

You got me wondering, too (I'm new to the GLK). According to Rockauto.com (my go-to for compatibility questions) they seem to take the same replacement headlights. Hmmm.

So I looked up what the two years actually look like - not much (any?) difference I can see...

 

OTOH, if you want to see the difference between the 2010 and 2013...

 

2013-15 GLK with halogen headlamps use reflector housings than the projectors used in the earlier models. I don’t know if bi-xenon was an option on the GLK.

 

"Bi-xenon" as in 2 projectors in each headlamp with HIDs for low beam and high beam separate? No.

But there is an optional ILS system with xenons and projector that have a shutter which moves to shift the low beam to a high beam. It uses a windshield-mounted camera to detect oncoming light to switch from low to high.

This system is awesome btw.

 

In BMW-speak, "bi-xenon" refers to the single projector with a shutter, not two separate projectors (which would be better, IMHO). I find it semi-pointless as the low beams project as far as the high beams, which essentially just light up the trees around you (and I suppose street signs). ;-)

 

I dunno, I find the MB system superior to most other lighting options. Having also had the BMW LED projectors "lighting package" on my X3, which was awesome BTW, the light output of the HIDs seems (to my eyes) better light that is closer to true daylight. The LED projectors on the BMW were great as well, they also had the adaptive auto-high beams which were convenient to have on when driving at night. But the light output of the LEDs seemed too bright, especially when bouncing off reflective road signs and especially in high-beam mode.

Both vehicles have the auto swiveling headlamps that "turn" as you steer; very nice feature.

I suppose the most important aspect is proper alignment of your headlamps - regardless of the type (projectors, reflectors, LEDs, HIDs, halogen, etc.) - as this will give you the most usable light in your specific circumstance. The balance of proper lighting to see where you're going when traveling at 70+mph vs not blinding oncoming traffic will continue to be a topic of debate.

 

My. 13 reflector (not projector of earlier years) was worthless in light output and was aimed way to high. Even re aiming down light output was worthless on the road. I put in 35w hid I aimed it all the way down , it lights the road and doesn’t blind oncoming traffic . It looks like the projectors could take a low and separate high beam bulb. I think HID would be great , if you aimed them properly. A 35w HID puts out 2.5x more light than a 55w halogen. They work.

 

My 5-series wagon has the headlights that self-level and turn. We do some driving in rural areas where there are nearly right-angle turns in the road, and the lights "preceding your turn" help a lot. Both this one, and my previous 3-series (330i ZHP) have HID projectors, and are amazing (the ZHP more than the wagon, for whatever reason).

The GLK had halogen projectors. I wasn't very impressed with them, to be honest. Especially because someone had muffed installation of the left bulb, so it was producing a dim blob about 10 feet in front of the bumper. ;-) Swapping them out for some (legit) high-power LED "bulbs" made a world of difference, both in the temperature (aka "color") of the light, and the brightness. Better yet, the LEDs were designed to mimic the output of halogen bulbs, so the pattern is nice. Even better, they are adjustable by rotating (after install!) so you can fine-tune the pattern even more. I ended up with a pattern that was much better than that of the halogen bulbs. If you're interested, here's a link to the video showing the install and the comparison of the two patterns...

 

Doesn't it seem odd that Mercedes downgraded the GLK's headlights in 2013, when they were refreshing and improving everything else? That's how it seems, anyway. The GLK's lighting package proved too elusive, so I settled for the stock lights. The pre-'13s had projector headlamps, presumably Xenon, while newer cars like mine got plain old halogen reflectors. My two Fords, otherwise identical, have those two different headlight types, and the projectors are much stronger, with a sharp cutoff. The GLKs headlight history reverses the positive evolution of my VWs, from the 1980s halogens up to my 2013 Tiguan, which had steerable HID projectors that were amazingly effective.

Did Mercedes choose to cheap out on headlights here, or are their halogen reflectors especially good? I've had few opportunities to drive my new-to-me used GLK on dark roads at night yet.

 

The 13 halogens suck, worst lights I’ve ever had. I put in 35w HID, aimed them all the way down , now they work. It was probably a us gov regulatory issue , but it was a mistake .

 

"Projector" headlamp assemblies can use different lighting sources including traditional halogen bulbs. I imagine that's what the base pre '13 GLK came with. Having said that, the projector assembly can provide better lighting than a reflector assembly.

 

My ‘13 C250 and ‘15 GLK350 both had reflectors with H7 bulbs. Compared to every MB we had up to then they were terrible. We couldn’t see neighbors walking their dogs at night 50 feet away on low beam. The high beams were just barely okay. I found that it’s basically the standard 55 Watt H7 bulb. The standard bulb Mercedes used was a Hella bulb that cost about $2.50. Higher performance H7 bulbs from Sylvania and Phillips which cost $12-$15 and are still legal at 55 Watts perform much better. “Cheap out” seems the correct analysis to me. The ‘21 GLB250 has LED lighting and has excellent forward nighttime visibility again.

 

Hid consume 35w but output 2.5x more light. Led would be good if you can find reviews showing a good beam pattern since leds light only one side. No halogens will really work, increase in light output is at the sacrifice of longevity, thinner filament is used. Lights are one thing you need to not burn out. Hid last the longest. 10x more than Halogen. LEDs might fail since heat is their enemy.

 

I'd suggest watching the video I posted above (LED with double-sided output, and a good pattern, actually better than the halogen bulb). Those "bulbs" I used (misnomer in the case of a LED headlight) are rotatable, which does give you the opportunity to fine-tune the pattern.

 

No doubts that the bi-xenon headlights are the best. But if you don’t have them, upgrading requires completely new headlamp assemblies. That’s difficult and expensive.
An easy way to improve the light output is to go with higher output H7 halogen bulbs. Habbyguy has tested some LED replacements that look like they work, too.
As far as the reduced lifetime, I replace my halogen headlight bulbs every 2 years. I don’t give them time to burn out. All halogen bulbs suffer from reduced light output over time. It’s due to sublimation of the filament and redeposition on the inside of the glass envelope. H7 bulbs throw a better pattern but have a lot of self-shadowing which reduces useable light compared to some other bulbs. If you start with a crappy intensity and it gets worse over time, it’s just unacceptable.
The LED lights on newer cars may not be quite bi-xenon level, but they are very bright white light. They are also designed to provide a wide pattern with a sharp vertical cutoff similar to the bi-xenons.
There may be some suitable aftermarket LED assemblies available for older cars, but I haven’t investigated.