Installation was about as easy as just switching out bulbs.
Much more light output and cutoff is not perfect, but very nice. A great upgrade over the crappy Miata stock lights

Having just one 7 inch headlight, I'm always looking for more light.
The S-V.4 realy deliveres.
Having treid a lot of diferent brands and performance statements, this one has a very good result.
Clear cutoff and very bright.

After doing much research on improving the lighting on my 1965 Ford Mustang, I decided to switch out the 7 inch round lenses for Hella lenses that used a replaceble H4 bulb. I then researched Headlight Revolutions extensive comparison bulb data base and settled on the S-V.4 V4 bulbs which I preordered. All I can say is that they were definitely worth the wait. While the Hella lenses came with a very good Hella Halogen H4 bulb, the S-V.4 V4 just blew the Halogen out of the water with a much purer whiter light that dispersed better and had better beam focus along with being 2.5 times brighter. I give this bulb my highest recommendation for anyone looking to upgrade their lighting system. A picture is worth a thousand words and I have attached photos of the S-V.4 vs the halogen right after installation of one bulb.

It's everything I wanted and not a thing that I didn't want!

The S-V.4 V3 was easy to install. I did have to modify the rubber boot. Noticeably brighter than OEM bulb. Thanks Headlight Revolution staff for the help over the phone.

Hard for me to answer your questions, I DID NOT received anything YET
Wondering if I should have bought lights down here

Installed the bulbs in less than 30minutes. Installation was straight forward and only issue encountered was body of bulb didn't fit thru the rubber gasket that is on my Honda HRV. After a small cut on gasket all ok. Bulbs look great & super bright!

Bought these when they were on sale. Last week, I finally got them installed in a 2015 Mini Cooper. They so much better then the stock lights and for that I am happy with them. I'm giving them 4 stars because they are now out of stock.
On a side note, I do have flickering when I start the Mini, and I'll get the faulty bulb if I use the "auto" lights position. Those are not the fault of the lights! But I will be contacting HR soon to see about getting the right Canbus to correct the flickering and hopefully the fault with the "auto" lights position.

first the packaging provides a clue to quality - blue ribbon here, form fitted foam in keepable box
second design of LED - fan cooled and chip selection VERY HIGH temperature limits which results in long thermal life
accuracy of chip placement - if chips are in same dimensional arrangement as filaments of halogen bulb to be replaced then reflector is used with minimal side glare - THIS IS EXACTLY dimensional to H4 bulb
brightness - by my measurements with "light meter app on Iphone" I get almost 9 times original lux of OEM bulbs
color - subjective but also objective - low Kelvin means low human eye response, VERY high Kelvin means blue low output and again less eye reponse - sweet spot is 5000K to 6500K, this measures out at 6000K from borrowed color meter
Canbus flickering - builtin driver circuitry suppresses flicker
BOTTOM LINE: instant on, perfect pattern, high output, superior color, long life
This is the current state of the art and a "best buy" or make that you had "better buy" before they are out of stock

I'm glad I waited to buy a set of LED bulbs to fit H4 reflector housings. The S-V.4 V.4 were worth the wait, for sure. I went from a set of 80/100 Hella bulbs in my car to these, and have been quite happy with the upgrade so far.

I would say they're easily brighter than my old 80/100 Hella bulbs, but not obnoxiously and uncomfortably bright. It's hard to be 100% confident on that since the colour is so different: these bulbs are almost too blue for my taste. I would prefer something a little yellower, honestly, and it would be terrific if they were offered with a yellower bulb as an option. I'm no lighting snob so my estimates are meaningless, but if good halogens are a 3500K and factory HIDs are around 4500K, these are probably a 6000K. They kinda look stupid in my old car next to the amber marker lights, so it may be time to change those I guess.

Low beam accuracy is probably 90% as good as with halogen bulbs: the cutoff is sharp and straight and wide, good hot spot right where it should be, but there seems to be a bit more stray above the cutoff than there was with the halogens. I assume expecting more stray above the cutoff is reasonable - even a brighter halogen bulb produces more stray light in the same housing, and these don't seem unreasonable and I haven't been flashed so I would give these a pass. After installation I did re-aim them from the halogen bulbs. I'm not sure if I never noticed before or if it's a "feature" of the V.4s, but the hot spot of the low beam is down and quite a bit to the right compared to the hot spot of the high beam. That's good, obviously, because it helps keep any low beam glare out of the eyes of oncoming traffic, but I did find that my high beams got A LOT better when I sacrificed the "classic" H4 low beam aiming procedure and concentrated on getting the high beams pointed dead ahead and level. I'm also a big fan of the single rectangular diode per side per beam, rather than an array of four or five square diodes per side - the output is very smooth.

With that said, the high beams are pretty fantastic. They're probably not the brightest but they're very bright and they PENETRATE! Switching to high beams throws them WAY down range, and the low beam shuts off like they should when high beams are on. If I were driving low speed, twisty roads at night I'd maybe concede the benefits of a Bi-Xenon retrofit, or would add some LED fogs wired to optionally stay on with the high beams (or maybe these can be spoofed to run all four diodes at once?), but for straight dark back roads these are just perfect - your eyes are drawn up to the horizon and there's just enough peripheral light to keep everything close up visible. I was pretty concerned about how these would work, but they suit the needs for the types of road I'm on. (The instant and dramatic change between low beam and high beam is pretty sweet too).

Installation was very easy - the H4 adapter ring is held onto the main "bulb" shaft with a spring loaded ball detent and it just pulls off. You install the ring into the reflector and slide the "bulb" in, give it a little twist to ensure the detent ball seats in the proper hole of the ring, and then deal with the wiring. My housings have a screw-on dust cap but there was plenty of room to snake the wiring and the control module around so I didn't have to modify anything, but if I had to I could have pulled the grommet in the back of the housing and run the S-V.4 wiring into the housing via that hole & made the connection outside. It was a no-brainer.

There is a fan on these units but I haven't heard them at all - physically or electrically - and I've never noticed the circuitry adjusting the output as though they were overheating. They're fully enclosed in my housings, but there's a lot of air in there so it'll probably take a long time for it to warm up, and it's not like the've had a chance to get hot since I installed them in Mid-December.

Yes, Mid-December, driven every day, headlights on 100% of the time. 3.5 months would have been enough time to blow one or both of the 80/100 halogens, and these are still going strong. And cheaper than most top-shelf competitors.