Bjbpe

Once this three-day snowstorm gets by us I hope I can put the car back on the road. Here in WY we have heavy wet snow when others are having spring. The lights in the car are stock 87 bulbs and they look a little dim over what they used to be. What's the best replacement bulb? What's the second best replacement (just in case the first is way beyond my budget? For those who think I might be a tightwad - damned right - my budget is severely constrained by the government.

Bill Ball

Unless the regulations regarding H5 (9007) bulbs approved for road use changed recently, none are substantially better than the others. They are restricted to 55W low beam and 65W high. My temporary solution was to ask for off-road bulbs at my local autoparts store (they are sold behind the counter). Those are 80/100 and do provide substantially more light. I ran them for 3 or 4 years with no issues, although some have expressed concern about the extra wattage with stock wiring. Eventually I switched to H4 (Euro headlamps) and installed aftermarkets HIDs. None of this is technically legal, but with so many cars coming with HIDs these days, I've never had any issues. However, I do NOT recommend HID conversions with the stock US DOT H5 type lamps. The beam pattern is way too diffuse and will do nothing but annoy oncoming drivers.

Now, since you say the bulbs look dimmer than they used to, what you need to do first is remove the lamp housings and check the condition of the reflectors and clean them and the inside of the lens, and clean the electrical contacts as well. Check the bulbs too. If the glass is cloudy or silvered, replace them.

FredR

Osram make some very effective bulbs- Night Breaker Plus in H4 form factor that I intend to fit soon- 55w rating but seemingly much brighter than stock. No idea if they make similar in H5 to suit your market but you might research it. I have something from Osram that is better than stock and these are purportedly better than the upgrade I fitted.

Legality, suitability etc down to you.

Regards

Fred R

Bjbpe

I've been confused (age does that to you) about the various "H" numbers. My vehicle was set up for the USA with it's peculiar laws and it's peculiar politicians. Which ones are which?

m750rider

In my 91 S4 with H5 lamps I use OSRAM Sylvania Silver Star Ultra. They are not that expensive, available at most auto parts shops, and work fine. Try those to start and make sure your headlights are aligned properly.

JHowell37

Halogen bulbs get dim over time. Don't believe me? Replace just one and turn on your lights and compare the light from the new bulb versus the old one. If the old bulb has been in service for more than 2-3 years, you'll see a noticeable difference.

Bjbpe

Thanks guys. Some good tips.

The_Remora

Was doing some research on replacement H5 bulbs. Not looking to go HID or H4 conversion at this time, just best (for me) practical and economic purchase. Was just reading some old threads here and elsewhere on best H5 bulbs and see lots of noise on the 'ultra white' blue tint bulbs. In fact those seem to be most common recommendation and saturate the online headlamp store popups. But upon further reading, they certainly don't seem like the best choice. In fact they seem like a light manufacturers dream in that they're popular, easy to sell, and they only last a small fraction of the life expectancy before needing replacement so they get to sell them over and over again. And, they produce less light output and fry the connections due to having to use higher wattage to overcome the blue coating, and they net less actual light than clear bulbs. Here's a link to a good article on this, figured I'd share it here.
http://www.danielsternlighting.com/t...good/good.html

jcorenman

And light scattering increases dramatically with shorter (more blue) wavelengths of light (scattering increases as the 4th power of 1/wavelength). So any haze or fog and all you've done is to double the glare coming back at you.

When means the French were right, with their beloved yellow fog lights.

The best bet, I think, is any of the brand-name H5 bulbs and save your money for a pair of H4 Euro lights.

Fogey1

Headlights as well as foglights and yes, they were and are (still, I think).

I grew up with yellow Marchals and they were great. The French are easy to ridicule but they've come up with a lot of elegant engineering solutions, like hydro-pneumatic suspension and the first four-valve head.

Also, Daniel Stern knows his stuff.

Will

Fogey1

Here are couple of informative threads:

https://rennlist.com/forums/928-foru...t-upgrade.html
Headlight upgrade

https://rennlist.com/forums/928-foru...-into-lhd.html
H4 Headlights from RHD Car into LHD?

snoz

This is very true. I worked in a photo lab during college. The printing machine used a halogen bulb similar to what you'd find in a data projector of today. Every morning before starting to print pictures I would have to "balance" the processor. One of the steps was to turn up the juice to the bulb. Eventually it would get to the point where you couldn't turn it up enough to stay in spec and it had to be replaced. It's a gradual dimming but very linear if I recall correctly.

ROG100

They dropped the yellow headlight requirement some time ago.
928 lights are still available in yellow if you feel inclined.

I have some very nice sets of used LHD H4 8" for $500 the pair 8>)

danglerb

I've read some reports that SEMA this year had the first gen of LED replacement bulbs for headlights in all the usual shapes and sizes. Might be a way to go for those concerned about color of light.

jcorenman

It will be interesting to see how they manage the heat that gets generated. Incandescent (halogen) bulbs generate a lot of heat (more than LED's, per lumen) and run very hot. But the quartz/tungsten bulb likes high temperatures, which means that most of the heat can be dissipated by radiation (the heat you feel in front of a headlight) and convection (heating the air within the lamp housing).

LED elements cannot run nearly that hot-- they would melt-- and need serious cooling, i.e. a heat-sink arrangement to carry the heat elsewhere. Take a look at the 7" LED headlight-replacement, the whole backside is a metal heatsink. A water-cooled heatsink could also be used, with tubing, a pump and a heat-exchanger elsewhere, or heat-pipes (with a nearby heat-exchanger) as used on laptop PC's to cool the processor. I don't see how to fit all that into a H4 or H5 bulb package but it will be interesting to watch developments.

The other issue is that a better/brighter/more-efficient light source in a H5 lamp assembly is still a crappy H5 lamp assembly. The light-cutoff for low beams is poor, sending a lot of light ahead and upwards. Making the source brighter sends more light to the road, but also sends more light towards oncoming traffic, which blinds them and they crash into you. Which is counter-productive.

The Euro H4's are a much better solution. The bad news is that the 8" lamp assembly is unique to the 928, the good news is that Porsche seems to be dropping the prices. If you shop around (e.g. Sonnen) you can get a pair of new H4's from Porsche for less than $520. That's still pricey, but better than it has been.