H4 VS H5 comparison
 

Ok I have had the joy of being able to compare h4 and h5 back to back and wanted to give my thoughts so those considering would have more info available.

I found that the h5s though not as concentrated provided just as much light as the H4 with not even close to the expense after driving 2 cars back to back I really could not tell the difference. both lit up the night just as well.

Any other thoughts out there? Really wanted some honest opionions . I have considered changing them out but after this I dont think so though I would like HID I believe you have to use h4 so you have 1k into that swap.

Interesting....I was curious about this topic.

I just installed the JWest relay kit plus replaced bulbs with the best modern Sylvania bulbs available and have been quite please by the results. Road seems well lit. At this point I'm not sure the $500 plus to convert to H4 would be worth it to me. Maybe somewhere down the road..

Take a look at the light pattern when you're driving down a very dark road. The H4 has a very crisp line of cutoff at the sides and the front. The H5 just bleeds light everywhere.

Having clean lenses is important too. The cloudy H5 lenses can make the lights a lot dimmer. Kind of a hassle to clean but it does make a difference.

I have h4s and relay kit jest and using 80 85. Watt bulbs. Great light compared to the stock 55 watt bulb. What I noticed is that the lens covers are exactly the same the same equals that the way the glass is made with all the molded lines on the inside I'm assuming is for throwing light in a concentrated effort. If they are both the same it seems impossible to get balanced light coming out of them on the right side to the left side. Anybody else notice or wonder about this. Also while your in the h4s you'll see 3 rubber little nipples which 2 are for adjustment and 1 is for holding the reflector. Anybody know of a part number for these 3 per headlight 6 total can be purchased

probably that it looks that my h5's are near new. I just was nto seeing a huge difference worth the expense to change them out

yeah I need to figure out a relay system for my 964 as no one has one premade.

I would think that you could use the kit as a basis - the theory and implementation is the same, all you need to know are the wire colors and the routing.

I think another thing to keep in mind is the metal reflector housing of the Euro H4. It lets you run flamethrower wattage illegal bulbs. The H5 reflector/lens housing is plastic and it will melt.

I put 80/100 bulbs in mine and wow that's some light. I suspect the substantial wattage increase like that biases my impression of the H4 vs H5. I always ran my H5 with std. wattage bulbs. So they would of course look dim in comparision to the high wattage H4 install I did.

The H5 lense cleaning problem is the major reason why I chose H4's. The H5's always seem to look milky, dirty which you rarely see with the H4 lights. The milky, dirty look also seems to be favored by all newer cars, even the ones with HID lighting. Do they actually have plastic covers instead of real glass?

This past weekend I installed the "Hella H4 Halogen Headlamp Upgrade Kit" from our host. Part was 70476-M44. Bulb is 55/60 watts.

Car is a 79 930, the kit was ~$55/light. Light is better directed and seems much better for night driving compared to my previous sealed beams.

Question: What is the difference between the kit I installed and the expensive "H4 Upgrade" that is $250/light? What do you get for the extra $400?

Here is a photo with h4 thingy installed on the left, on right is sealed beam.

http://zakthor.files.wordpress.com/2..._23_38_031.jpg

Lightwise there is probably not much difference because the Hella H4 sealed beam bulb repacements are a similar in the light design compared to the Bosch H4 lights. The Bosch ones, which are a complete light fixture assembly, are the same as used in Europe. The Hella H4's are mostly used here as a less expensive replacement for the sealed beam bulbs inside the "sugar scoop" assembly. I, myself, do prefer the appearance of the Bosch H4's because they look more streamlined.

I have H5's on my SC .. switched from the sugar scoops .. I also did a really set up about a week after I did the headlight and that made a difference .. also running the silver star ultras ...

But the thing I do know about H5's is you do not have to worry about them falling out on you ... you would have to hit a big pot hole to shake a H5 out ...

H4's on the other hand ... watch the bumps .. it happens .......

+1 on what porwolf said. Light quality between the two with all other factors being equal is likely not readily apparent.

The difference between the sealed beam replacement H4s and the pricier Euro H4s is most readily identified by the larger and more aerodynamic looking lens.

Euro H4:

http://forums.pelicanparts.com/uploa...1332820901.jpg


Sealed beam replacement or Sugar Scoop H4:

http://forums.pelicanparts.com/uploa...1332820933.jpg

The lens itself is glass. The lens is bonded to the reflector housing, which is silver/reflective coated plastic.

Melting the reflector is only a problem with high wattage bulbs. Stock 55/60W bulbs don't seem to be a problem.

I'm gonna' have to be careful with this 80 watt arrangement (not installed yet, BTW) in my H5 environment (in fact, brand-new headlamps on both sides). Apprently, it's simply NOT enough to have a high temp socket that can easily handle the heat (there).....but being aware of the internal coating limitations (heat) and "thingamagig" (reflector?) on front of the bulb on the present H4 assemblies?

What are their (factory) heat limitations, in terms of bulb wattage?

I want to be cautious here, as I wasn't aware of these limitations.

Thanks,

Doyle