Better headlight lighting.....


First off, I have to apologize, this isn't strictly GT40 fact, not at all.

I'm trying to get better headlight lighting in my automobile - looking for brighter basically. Rig is a 2002 Chevy Suburban I bought new (260,000 miles now). The old school incandescent headlight lighting isn't great. I should get a new Suburban but I really like this old rig and all the family history with it. My kids and their friends grew up with this rig - school runs, skiing, family road trips, thrown up in it, slept in it, etc.

I've been trying to find out how to improve the lighting with the newer technology available today. There seems to be a ton of advertising and marketing out there, but not a lot of non-commercialized discussion of what are the pros/cons. I trust the first hand experience of the readership here on GT40s.

Anybody have some experience with this stuff that can share some insights? Would really appreciated it.


Randy V

Staff member
Lifetime Supporter
I've done some successful experimentation with various brands of LED retrofit bulbs.
I can't say what will work on your particular reflectors, but look for bulbs that are replacements for your precise bulb size/style - don't accept something that works to replace a variety of different specs.
Also - be wary of sellers that say that their lamps are "DOT Approved". Why? DOT does not "approve" anything. What they do is to create a Specification that is a DOT Spec and manufacturers create their product to that spec.
Something else you may want to consider is replacement with a high quality halogen like the SilverStars from Philips and others - then work on your FOG or Driving lights to replace with LED.
Still yet another alternative is to buy a high quality LED Replacement housing that utilizes projector lenses.

Moderator note - I am leaving this here as the information within is certainly applicable to GT40s and others.
Do some Googling. I had replaced the bulbs in my Excursion with some Amazon LEDs....they were OK, but there was virtually NO difference between low/high beam. I didn't get "flashed" by on comers, but they were only a little better than the halogens. After seeing an online video about LEDS, I came to understand that "more LEDs," multiple "sides" etc. do not produce more light. The key is that the origin point of the light must match the point of the halogen bulb. Thus, the distance from the mount and the indexing of the light source is key. If the light source is not at the correct point the reflector and lens prism cannot direct the light as intended. I replaced the $30 units with some highly rated $100 units and WHOA! More light, proper beam cutoffs and a huge difference between low and high beam. Took me some time to index the bulbs in the headlamp housing, basically a "trial and error" process, but well worth it.

Ian Anderson

Lifetime Supporter
Make sure you are getting the full voltage at the bulb ….that positive and earth are both good connections and can handle the current draw.
I had to upgrade the wires in my GT40 as the better wattage upgrade halogen bulbs drew too much current for the wire.

I have not done this but have heard of other going this route with their cars.
There are aftermarket xenon projectors that you can get. these can either be fitted stand alone or vie modifying the original headlight buckets. I think the likes of Bosch/Hella make these as an option. They are often fitted to busses and trucks. I am very interested in options to fit the original style housings typically used in GT40s though. I'm guessing a H4 or H7 style globe but have not looked or tested anything yet.

The best passenger car lights i have ever had, were BMW E90 Xenon adaptive lights. These would turn as you turned the steering wheel and had auto high beam function as well. They would quickly drop to a lower height which was done via a mechanical shield that restricted the spread of light. As soon as the oncoming car went past, it would quickly flip up again. It gave a very sharp cut off and a very intense focused beam. Range was excellent.

I traded this vehicle for a Mazda CX-9, which has similar technology, but it functions differently and does not have the mechanical shutter. The beam does not seem as bright or as focused. range is also not as good either and It's hard to tell if its switch between high and low beam in auto mode as it seems to do it via sensors to detect where the oncoming light is and just dips that quadrant only. I would like to try one of the newer BMW's again.
I don't know what bulbs your car uses, but if they are H4, replace them with 9012/HIR2 from Vosla and you will nearly double the output of your low beams. Use Toshiba 9011/HIR1bulbs for your high beams and you'll pick up about 50% output. I've spoken with a lighting consultant, placing LEDs in incandescent housings will not yield a good result because the point of light output is different and incompatible with the reflector.
Thank you fellas, this is very helpful information - have some idea where to go now.

The bulb is a 9006....standard headlight bulb for a 2002 Chev Suburban. I did install the best Sylvania bulb a few months back - think it was their "Ultra" bulb. That was an improvement over what was in there previously. Just looking for a little more brightness now.
Biggest issue with the LED replacement bulbs is where the actual incandescent bulb filament is vs. LED chip placement is relative to the reflector dish behind it, so the light is properly reflected from rear bowl into the clear lens in front with its focus correction ferrels. I have a set of Lucas 576 Flamethrower driving lights on the front of my Cobra that I retrofit with new bulbs. I look like a meteorite coming down a dark road, light across both sides of road (for deer, etc). No longer a focused beam as originally designed. You can shim the bulbs back towards the reflector if necessary to focus.