Boslla Bullet 4-Mode LED Headlight Kit Review

August 17, 2019

PLEASE NOTE: Results and recommendations on this page are based on our version 1.0 test bench. For the latest results, please see our test chart and recommendations pages which are results from our version 2.0 testing.

RECOMMENDED FOR: All Headlight and Fog Light Styles
RANK*: #3 (tie) in Reflector Headlights, #2 in Projector Headlights, 65 total LEDs tested
*as of this review, for the latest facts check our recommendations here

When Boslla reached out to us to review their ‘Bullet’ product, we weren’t honestly that excited. We have seen all the marketing and assumed their popularity due to the hype. Once we received the product in hand and started testing however, our thoughts changed very quickly. To our surprise, they performed extremely well! Boslla only sent us a sample to test, nothing more. This review is completely unbiased and true, as all our reviews and tests, as always.


The major benefit to these is the switching mode. They start off white (Bosll calls this mode Sunny), and from there you have the option to switch them over to white/yellow (both LED rows enabled, called Snowy), then yellow (call Fainy and Foggy), and finally a strobe (on/off) pattern (named Warning Flashing SOS Rescue). To switch, you simply switch them off and then on again for the new mode(s).

Headlights are very sensitive to the LED positioning, and having a switching feature like this poses a problem, beam pattern. You’ll want to install the LED bulbs into the position which casts the beam correctly (see figure 1), otherwise you wind up with a highly incorrect beam (figure 2). Ok perfect, just install them correctly and all is well, right? For a single color yes, but when it comes to utilizing ANY other color, you wind up with an incorrect and blinding beam. See figure 3, which is the ‘4300k’ mode, rather two colors sitting on top of each other ( ~6000k white & ~4150k yellow based on our color meters, and a mixed average of 5100k for ‘4300k’ mode). When the bulb is installed correctly for one color (say yellow), moving to the other color again produces an incorrect beam (figure 4).

If you are installing these into your fog-lights, we’d recommend rotating them for the white color. You may ask why not yellow, as the warmer color cuts through fog, snow, rain, etc. much better? The reason is that they start off on white mode, and there is no option to change the default on color to yellow. This will provide a correct beam for white, and a higher than normal beam for yellow (and white/yellow), but in inclement weather this is beneficial to your visibility. You could alternatively set the correct position for yellow, but you’ll have to change them over to yellow through the modes every time your fogs come on. If your fog-lights are off by default and you don’t turn them on every time, defaulting to yellow may actually be best.

There are not many LED kits out there that offer this, and while this feature isn’t perfect, it’s a great addition to have when you need it out in the backroads or country roads, we just don’t recommend using the other modes with other traffic around, for the safety of everybody.

Yes there is  'strobe' or 'warning/flashing' mode which uses the yellow diodes, but we don't much care for it personally. It can be distracting if turned on accidentally while driving. If you are into it though, by all means, have fun, but be safe.


Reflector Beam - White Mode

Reflector Beam - White/Yellow Mode

Reflector Beam - Yellow Mode

The Bullet’s scored a 5.1 based on our tests, which places then at #3 overall (tie), and #3 for premium products. Pretty incredible for a switching “ 4-Color LED” product, as they call it. They produce about 3.3X more light output/distance (lux) in low-beam reflectors, and a very respectable 2X (+107%) more light in a high-beam reflector, which is actually the highest we have tested so far (in high beams). High beams are always tough, as they are typically very good halogen bulbs with a higher wattage, which is why you will not see nearly the gain upgrading your high-beam vs. low-beam.

Glare is minimal when positioned correctly, and we subjectively rated these at 5 stars for the bem pattern, a perfect score. The LED chips are very small and in-line with the best products. The beam was nearly identical to a halogen bulb. They seemed to spend some time ensuring the diodes are perfectly lined up with the original halogen bulb filament. We didn’t see much about the beam on their website, but it really deserves some great credit. Again though, this is in with only ONE single mode where the bulb is installed/rotated to. Switching to any other mode possesses the wrong beam. Very important to keep in mind.


Projector Beam - White Mode

Projector Beam - White/Yellow Mode

Projector Beam - Yellow Mode

For those with halogen projectors looking to upgrade to something brighter, the Boslla Bullet does not disappoint. We scored them at a 4.8 overall, with just over 3X (+208%) more light in the low beams, and an incredible 97% more high-beam light (if you have bi-halogen, or a separate high-beam projector). The typical dark spot in the beam (near the bottom) for most LEDs is present here, but it’s pretty small and on par with most others. It’s rare to have a perfect beam like halogen or HID due to how LEDs are designed, but most people won’t notice it.


We can talk about color all day with these bulbs, but we’ll get right down to the facts.

In white mode, they averaged about 5750k.

In ‘4300k’ (white/yellow) mode they averaged 5500k, but 4900k on another meter of ours. It’s hard due to two colors essentially being used at the same time, so there is no ‘real’ kelvin temperature to provide here, just an average mix of white and yellow.

In pure yellow mode, we found the color to be around 2950k, a very strong yellow, which will work great for fog situations.


Lumens are the total light output of the bulb, and the Boslla Bullet’s produce a very high number of 4210lm (measured each bulb) in white mode, giving a total of 8420lm for a set. In yellow mode, they were a bit lower at 3925lm/ea (7850lm/set) albeit the lower kelvin that normally produces a higher number. The yellow chips are strong, but not as strong as the white diodes. In white/yellow mixed mode we saw a total of 9532lm/set (4766lm/ea). Not quite as high as you’d expect, but we presume this was due to a limitation of power, and a conservation setting for heat, so they don’t overheat running two rows of diodes at the same time.


The Boslla Bullet’s use a Philips chip according to Boslla, most likely a top line model based on the brightness they produce.

Power ranges from 26.6w – 28.1w depending on the mode. Very efficient design. White/yellow uses the lowest at 26.6 watts, while the white mode runs at 28.1 watts, with yellow using about 27.9 watts.

Temperature is well within reason at only 109°F (vs 160°F for halogen) with the well-equipped fan. Ambient temperature taken during enclosed runs inside the back of the headlight (dust caps, fully closed headlight) is about 99.5°F, also very cool, and no reason to worry.

Noise isn’t an issue at only 63db, they are some of the quietest LED bulbs we have tested yet. Just be sure they are secure in the socket to avoid vibrations.


The Bullet’s are fully dimmable on the popular PWM circuit most vehicles use nowadays, and on a standard line, they dim all the way down to 6.3v. Can you run them with your vehicle’s DRL low or high beams? Most likely yes!


If you are installing into a vehicle that utilizes a bulb-checking system like the very popular CANBUS (Audi, BMW, Chrysler, Dodge, Jeep, Ford, Lincoln, Cadillac, Chevy, Mazda, Subaru, etc), you may see a bulb out error with these due to the lower wattage draw vs a halogen bulb. A great way to check, is to simply pull the bulb you are looking to replace out, turn the key on, and see if you have a bulb out error on the dash. If you do, you’ll need an in-line capacitor, commonly called ‘Anti-Flicker’, ‘Decoder’, ‘Error-Free Decoder’, etc. Universal and other brands should work well to help rid the false error. 

Boslla sells their own Capacitor add-on which you can find here:


These offer 100% clocking by allowing you to rotate them by 1° at a time, virtually at any angle you need. There were only a few products that offer this, and the Boslla Bullet are one of them. Some headlights set the halogen on a slight angle, and in some cases this does not work well for the LED design thus requiring you to rotate just a bit (diodes should typically be facing exactly left to right in both reflectors and projectors) in order to get the perfect beam you need for best visibility.

As with all aftermarket LEDs, you’ll want to consider the size available for the extra components including the rear fan/heatsink and driver (in this case external driver). In most cases you can fit them without issue, however for certain vehicles that have very tight fitment for the halogen, you’ll need an extended dust cap (you always want to keep the headlight closed if that is the original design). For the Bullets, they are on the smaller size in terms of length from the base to the rear at 34mm. Maximum width of the fan/heat-sink is about 36mm, and the length of the diode base is about 37mm, smaller than most. The external driver measures 55x30x13mm, so keep that in mind when you install as you’ll need room to mount or tuck that inside the headlight housing.


Boslla gives you a standard 1-year warranty. Not great in our book, but on par with most others. For this price point though we expected a longer warranty. 


The Boslla’s have been around since around August 2018, so the brand is fairly new, but they perform extremely well, and seem to be of decent quality in terms of material. Just keep in mind how you’ll use them with the 4-mode options by mounting them correctly for the mode you’ll primarily use and keep other drivers in mind when changing modes. Boslla seems to have sales on these, so if you can pick them up for a discount, they are well worth the money for those who are looking for a multi-mode LED product, recommended with respect to the caveats mentioned

Full Test Details & Facts

  • White Mode Low beam Reflector Lux (per): 5400
  • White Mode High beam Reflector Lux (per): 7360
  • White/Yellow Mode Low beam Reflector Lux (per): 3740
  • White/Yellow Mode High beam Reflector Lux (per): 4580
  • White Mode Low beam Reflector Lux (per): 4210
  • White Mode High beam Reflector Lux (per): 5730
  • White Mode Low beam Projector Lux Hotspot (per): 2700
  • White Mode High beam Projector Lux (per): 5880
  • White/Yellow Mode Low beam Projector Lux Hotspot (per): 2010
  • White/Yellow Mode High beam Projector Lux (per): 3640
  • Yellow Mode Low beam Projector Lux Hotspot (per): 2370
  • Yellow Mode High beam Projector Lux (per): 3490
  • Lumens per Kit: 8420
  • Low Beam Pattern Rating: 5.0 stars
  • Low Beam Reflector Glare Lux: N/A
  • Tested Kelvin: 5250k (white mode), 5500k avg. (white/yellow mode), 2950k (yellow mode)
  • Running Temp: 109°F (43°C)
  • Rotatable?: Yes, 1° clockable
  • Bulb Dimensions: 36mm, 34mm, 37mm (Max Width, Base to Rear, Diode Handle)
  • Heat sink Size: 55x30x13mm (WxLxD)
  • Noise: 63db
  • LEDs/bulb: 6/ea color (12 total)
  • Direction: Flat
  • Driver Type: External, removable
  • Wattage (per): 26.6 - 28.1
  • Cooling Type: Fan
  • DRL/High-beam Dimmable: Yes
  • CANBUS Compatible: No
  • Radio Frequency Interfearance: N/A
  • Warranty: 1 year

As always, our tests are unbiased and true. We are not like other sites with paid reviews or fake information. We always DECLINE paid or sponsored reviews and offers. Our goal is to provide you with our lab test details and let you decide what product may work best for your application. We simply ask that if you are going to buy a product we have reviewed, please use our affiliate link, as it allows us to further enhance our tests and of course test new products! -Blaise @ BulbFacts Team

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