4/17/24 3:42 p.m.

One of the things I would like to improve on the Molvo is night-time visibility. 

The car has standard 7" Sylvania sealed beams being fed by the Miata wiring harness. I don't know if it is me getting older or me getting used to cars with newer light technology, but the sealed beams are not cutting it for me. 

My first thought is LED technology since the required amps should not tax the existing circuit.

Are LED lights actually legal? 

Is headlight aiming more critical  with LED lights than with old sealed beams? I typically just point it at garage door and hope to be in the  ballpark.

Would prefer to keep the look closer to stock that what I see with some of the LED options. Don't like the halo look on a classic car.


I see prices and features all over the place if I look at on-line vendors for LED lights. What am I paying for with the more pricey products? Is there a recommended vendor/manufacturer?





MiniDave HalfDork
4/17/24 3:47 p.m.

There's a thread on this very thing right here on GRM......

06HHR (Forum Supporter)
06HHR (Forum Supporter) SuperDork
4/17/24 3:47 p.m.
MiniDave HalfDork
4/17/24 3:48 p.m.

Beat me to it! yes

4/17/24 4:19 p.m.

I do recall reading the thread about the H4 kits. And might be the option because the price is hard to resist. But those are still incandescent. 

The reason I did not go down that road initially is that any H4 install that I have done  in the past required bespoke wiring with relays and a dedicated power source. There is a wiring harness mentioned in the kit but I really wanted to keep this plug and play if possible.

My understanding is that LED lights will work just fine with the original current provided by the Miata wiring harness.

So who sells "Quality" LED lights?  For that matter, what defines quality in LED lights.

Trent PowerDork
4/17/24 4:29 p.m.

I have installed Holley Retrobrite 7" LED units. They weren't impressive compared to a decent Hella Halogen H4. They were like $275 for the pair.

I installed the $150 per bulb Phillips LED  and They were pretty amazing but one only lasted 2 months and when it was exchanged under warranty the replacement was half the weight, cheap feeling plastic and the beam pattern and color were noticeably different than the one on the other side of the car.


I have noticed any car with this style

is incredibly glaring on the road. It is like they don't have any beam cutoff. Plus they are hideous so that is another reason to avoid them.


This style is super popular in the mini community.

But I consider them too ugly to even try out. The pictures of the beam pattern and cutoff are pretty impressive though.


But yeah, the current Toyota deal on the Koito is impossible to beat. They are very good performing lights

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
4/17/24 4:33 p.m.

Holley Retrobrights. It's what I'm running on Miata 338, they look stock. DOT legal. Not as aggressive a cutoff as some of the good LEDs, but it's an okay pattern and they drop straight in. They replaced a set of GE Nighthawks aka Trucklites, which had a bit more of a hot spot and definitely looked weirder.

As for what constitutes quality, good optics (usually overlooked in the halo lights) that give good light distribution and proper cooling so the chips last well. Be aware that since they run cooler, they may have problems melting snow off the lens but that's not an issue here.

I find the color temperature of LED lights gives me better vision even if the pattern is exactly the same as an incandescent. H4s don't necessarily require relays, that depends on the wattage of the bulbs you're using. But LEDs definitely don't.

EvanB GRM+ Memberand MegaDork
4/17/24 4:36 p.m.

The LED sealed beams from CEC industries look very stock. The output isn't really much better than a halogen though from my testing, just a brighter white color. I can't really find anyone selling them online but if you are interested I could source a pair.

They are DOT approved so they are legal to use. 

4/17/24 4:43 p.m.

Thanks. That's two that I can look into. I like the stock look of the Retrobrights. I actually had a set of the newer funky LED lights in the headlight holes when I was building the car, and they looked silly with the P1800 style. Never got to the point of powering them.

I hate to admit/think that part of the problem might just be night vision as I get older.

4/17/24 4:58 p.m.

Had a quick look at the Holley lights. Kinda in shock at the price.  And that is for just one light. 


Living in Canada does have some downside when it comes to buying stuff. 















californiamilleghia UberDork
4/17/24 5:18 p.m.
06HHR (Forum Supporter) said:

anyone replace the H4 bulb with an LED replacement ?

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
4/17/24 8:15 p.m.
NOHOME said:

Had a quick look at the Holley lights. Kinda in shock at the price.  And that is for just one light. 


Living in Canada does have some downside when it comes to buying stuff. 


That's not a living in Canada thing, they're that expensive. You didn't say you were looking for the cheapest option :) For that, grab some of the Toyota H4s. Or, if you really want LEDs, look into a good H4 LED replacement. Either Diode Dynamics or Moromoto just came out with a next-gen bulb that looks really promising, we're testing some now. That'll cost you about half as much as the Holleys.

ggarrard GRM+ Memberand Reader
4/17/24 8:32 p.m.

I have Bosch H4 conversion lamps in both my 77 and 83 Datsuns without relays and have had no problems but Californiamilleghia's question has got me thinking....

Amazon Canada lists the Holley Retrobrights and, yes... they are not inexpensive...

adam525i GRM+ Memberand SuperDork
4/17/24 9:58 p.m.

My E28 BMW is a true euro car so it came with 7" H4 and 5 3/4" H1 Hellas from the factory which are still in ok shape. The factory wiring though only uses the low beam filament in the H4 and just turns on the H1 for the highbeams which pissed me off, if I'm going to have all those headlights I want all the light. Because of that and not wanting to improve the wiring to handle the extra high beams I am running LED's in those Hella housing and driving the H4 highbeams off the same circuit as the H1. To me the cut off looks really good on the low beam and with all 4 lights going on high the light is impressive. One thing I don't like with the majority of amazon LED's is the higher light spectrum (6000-6500k) that looks very blue, because of that these are the bulbs I bought and really like (5000k).

H4 LED (doesn't look available at the moment on, maybe has them)

H1 LED for anyone reading this and interested in those.

I also bought the Toyota H4 kit (cost me $30+ tax CAD at Hefner Toyota in Kitchener, buy these while you can!) and some day may install them and at that time I'll run LEDs too (figured if I had them that should be good deterrent for rocks taking out the Hellas). I know some worry about LEDs in regular old reflector housings and where the light ends up. Too me the cutoff seams pretty good with the above bulbs in Hella housings but to be honest, I don't really give a berkeley at this point. It is rare I drive this car at night, when I do I WANT TO BE SEEN. Add to that the number of new vehicles that blind you with their stock headlights and I figure, if you can't beat them, join them.

Along the lines of I want to be seen, I have also replaced my brake light and tail light bulbs in that car with LEDs too. Old wiring, crusty connections etc lead to much less than 14 V getting to the bulbs back there, with LEDs the LED drivers take care of that and still output the light even with a low input voltage.

Dusterbd13-michael MegaDork
4/17/24 10:21 p.m.

Hella h4 conversion in the duster with no relays. Holy berkeleynuggets batman. Incredible. Don't know why i put that off for 25 years....

bentwrench UltraDork
4/17/24 11:22 p.m.

Many LED setups are not DOT rated, they lack the low beam cut-off, and just dim.

I use DOT approved LEDs in my older van.

I keep one in stock always as a retrofit for older Harleys and a reduction in generator load.

4/17/24 11:36 p.m.

In reply to Keith Tanner :

Truth is I had no idea how expensive they would be. 100 bucks each would not have surprised me but three times that by the time they arrive is kinda nuts. In my mind at least. 

But don't let that keep you from offering the good advice that you do, I will adjust as needed.

gearheadE30 Dork
4/18/24 8:06 a.m.

I have retrobrights in one of my E30s, they work well but I agree with others on the beam hot spots. Not perfect, but I think that is the nature of the beast with a fluted lens and an LED light source to some degree. They're a massive step up over the stock sealed beams, but they're not quite as good as my other E30 with HIDs in the OEM ellipsoid lights. The H4s in the 924 offer much more even light than the Retrobrights, but I think the 5000k temperature of the Retrobrights does them a favor vs. incandescents. 

I have yet to find a drop in LED bulb that doesn't have a horrible beam pattern. 

Hella makes 60mm LED projector modules. They aren't perfect either, but they are tiny and have been excellent as retrofit units in my Suburban. At $127 each, I thought the price was pretty darn reasonable.


David S. Wallens
David S. Wallens Editorial Director
4/18/24 9:33 a.m.

7-inch H4 Hellas on both the Miata and 911. Very happy with them: light where I want it plus appropriate looks. 

HotNotch Reader
4/18/24 10:06 a.m.

I have several vehicles in my personal fleet with OEM sealed beams that have had a variety of headlight replacements.

1991 Toyota Pickup, 5x7 square H6054 beams- I replaced the sealed beams with JW Speaker sealed beam replacments with grid heaters in the lense.  By far, the highest performing option, but very modern looking.  Running a previously installed relay harness.

1988 Honda Accord, 5x7 square H6054 beams - I replaced the sealed beams with a cheap set of Amazon E-Code H4 housings, with H4 LED bulbs.  Output is increased, the E-code beam pattern was largely maintained.  This car is my winter beater, and I have had to replace the H4 bulbs once in the last 5 years, as they corroded from the winter salt and started getting dim / flickering.  Pretty happy with the budget upgrade.  No wiring upgrades, everything functions as it should on factory wiring.

1985 Ford Mustang, 4x6 square H4656 beams - I replaced the sealed beams with a cheap set of Amazon E-Code H4 housings, with H4 LED bulbs. Once again, output is increased, the E-code beam pattern was largely maintained.  I replaced the inner high beams with a set of halogen pencil spots.  Pretty happy with this, although with no fender liners, after 6 years the inner material in the E-Code housings are discolored and deteriorating, although performance is still acceptable IMO.

1969 Lincoln Mark III, PAR46 5-3/4" Sealed beams - Once again, I replaced the sealed beams with a cheap set of Amazon E-Code H4 housings, with H4 LED bulbs.  On this I have the inner beams wired up to engage both the Low and High chips of the LED bulbs when high beam is engaged.  Very happy with this, although it's a bit unfair of a comparison since it's effectively quad beams when high beams are on, but it's like driving the Sun. No wiring upgrades, everything functions as it should on factory wiring, with reduced consumption.

1995 Chevy Cheyenne WT, 5x7 square H6054 beams  - 10 years ago, I retrofitted a set of Pilot plastic clear housings with a set of H1 HID projectors.  While it was good for the time, performance is lacking, the wiring and install is invasive and takes up space, and cost is roughly the same as a modern appearing set of decently performing LED sealed beam projector housings.  I plan to replace these at some point with a pair of well reviewed ~$100 LED projector sealed beams.

I've had little issues with LED H4 bulbs in E-Code housings.  Only issues I had were environmental, and I'm not sure that an incandescent H4 bulb would have performed any better.  The 85 Mustang is a dedicated Autocross car and I suspect that the vibration and moisture would have killed a few incan bulbs by now.  Again, the failures with the Honda is more environmental, as it gets relegated to salt duty and then usually sits the rest of the year.

TL;DR - a decent set of H4 LED bulbs and E-Code H4 housings give good performance.

TheTallOne17 Reader
4/18/24 11:12 a.m.

I run 6 of these on my lemons car for 24 hour races. Their cutoff is very good, high beams are noticeably brighter. I don't know about longevity, because we've only run them for 16 hours or so total across 2 races. They aren't pretty when off though 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
4/18/24 11:15 a.m.

NOHOME, I don't recall what Miata gave its life for the Molvo, but if it was a non-airbag car with straight stalks on the combo switch it has different headlight wiring than others. It'll run 130W high beam H4 bulbs without complaint - BTDT.

I ran e-code H4s in my Miatas for about 15 years before getting my first set of Nighthawk LEDs. I still have a drawer full of quality bulbs ranging from 55/60W to 90/130W. I haven't tried a set of H4 LED replacement bulbs, but I find the LEDs much easier on the eyes than the old incandescents. They may not be brighter, but I can see better.

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