Change of direction for my lighting mods

I wrote the federal rule on DRLs. The main reason that fog lamps are not allowed to be used is that the States wrote to NHTSA to not usurp their authority to regulate auxiliary lamps such as fog and driving lamps. NHTSA, not having the authority to usurp State laws unless there was a legitimate safety reason determined that it could not allow fog lamps as DRLs when writing its rule that only allowed DRLs. It the NHTSA were to mandate the use of DRLs, then it did have the authority to overrule States' laws where necessary for public safety.

Secondarily, the fog lamp beam pattern when aimed correctly per state laws, does not shine enough light into other drivers' eyes to make them conspicuous enough during the daytime.

As far as making them more effective as fog lamps, putting yellow paint on the lenses only reduces the volume of light emitted from the lamps. It acts as any other filter does with white light; it selectively filters out everything but yellow, so the lamp is actually much darker than it was originally. However, if you were to purchase a replacement bulb from Philiips, GE, Osram-Sylvania that were designed as an "all-weather" bulb, it would still have legally compliane output, regardless of the method to achieve the yellow color. (In essence, the filament, gas fill and glass envelope are designed in conjunction to make the filament run hotter, and emit more light flux such that when filtered by the yellow tinting, that it still puts out the correct amount of light, i.e. the same amount as the bulbs that are already in your Prius.

As far as yellow light being better for seeing, studies have shown that that is bogus. There are also studies that claim that blue light is better for seeing. All the claims really are about getting people to buy more expensive bulb more often. Why more often? Because in order to get the same amount of light out of the tinted bulbs, the manufactuers must run the filaments hotter and their life is much shorter than the OEM bulbs.

I agree that the Prius fog lamps are minimalist devices. Current ECE regulations and Society of Automotive Engineers standards (that States reference for regulating fog lamps) require very minimal performance, however they also allow very high performance, too. Unfortunately for most of us, OEM stylists don't like large lamps (too gaudy looking) and higher performance smaller fog lamps cost more (so the bean counters don't like them.) Additionally, with Prius that have HID, fog lamps in general are like having "t.... on a bull" interesting but useless. Also, even with the halogen headlamps, I bet you can hardly tell that the fog lamps are on. Thirdly, the best use of foglamps in when you can turn them on only with your front and real position lamps (parking and tail lamps). That way when you are actually driving in rain, snow, dust, smoke or fog (the only legal times that foglamps are allowed to be used under State laws) you can actually see under the interveining drops, flakes, particles, and etc.

One thing that you may be temped to do is to use a "high-wattage" bulb. While that might give more light output, it may not continue to achieve a fog lamp beam pattern. Also, because the Prius fog lamp housing is very small, it might not be able to withstand the increased heat load that the higher power bulbs achieve. Your lamps may slowly melt, deteriorate in other ways, or even worse, cause a fire in the wiring harness. relays or switches if they do not initially blow out the fuses. Besided, they use more power and decrease your mileage.

Why can't you turn on just the fog lamps with the position lamps? Because the lowest common demominator for state fog lamps use laws is the use of them with the headlamps on. Thus, many manufactuers build their vehicle such that the only way for you and me to use our fog lamps is the way that is legal in all states. Alternatively, some companies allow us to use them with the position lamps only or with headlamps and allow us to decide when to use them based on our state law. Thirdly, some manufacturers allow us to turn them on when ever we chose, hoping that you don't get a ticket for misuse and sue them for not wiring the vehicle in a way that helps you not violate state law. The reason for this hodge podge is that there is no federal law that dictates how, thoughout the U.S., fog lamps should be wired.

The consequence is that it is proven by observational studies that drivers misuse their fog lamps most of the time by having them on either always at night (regardless of the weather) or alway, period, because they can be turned on.

My learned suggestion to Prius owners who want much better fog lamps is to purchase true "projector" optics fog lamps from a legitimate company such as Hella (but not its "Optix" brand of lower performance devices.) Get the largest projector lamp that will fit in the opening of the bumper cover. A great place to see and purchase lamps is from: Susquehanna Motorsports Home Page (a.k.a. Susquehanna Motor Sports). Make sure that you purchase lamps that use the same or lower wattage light sources so as not to overload the wiring or reduce fuel consumption.

I like high performing headlamps, but I don't like glare either. Make sure that what ever you do, that your OEM headlamps and foglamps are aimed correctly. That way you will achiever the best perfomance from your lighting that it is intended to acheive.

 

I still think the greatest weakness of the stock foglights is the reflector design or the beam pattern.
Here is the Prius' fog light pattern:

I would rather see a cleaner line straight across. Like this pattern:

 

Rich, thanks for your excellent post. This is what I like: solid information from a reliable source.

As for your comment on yellow lamps, the French used to require yellow headlamps for all of their supposed benefits. Subsequently the French government realized that there are no benefits to yellow headlamps and now they use white.

Tom

 

That is exactly the issue. While they meet national and international requirements, they are not intended to be remarkably fine examples of fog lamp performance. As such, that is why, in part, I wrote the lengthy post.

 

Tom, I participated in the ECE regulatory amendments that changed that law. I was told that one of the underlying reasons for the change in the mid-1930's to selective yellow headlamps was to provide an indication of who was French and who was not French. That way you knew who's car to shoot given the impending invasion of non-French forces before and during WWII. And, oh by the way, we know that we can see better, lets just not tell them who we see better!

p.s. thanks for the compliment

 

BTW, the closest that you should view headlamp, foglamp, and driving lamps beam patterns is 18.3 meters and 25 meters is even better. Those are distances used for designing the optical (beam pattern and intensity) and aimability performance of such lamps. So that we can better compare photos, they should always be taken with the vehicle within those distances for the viewing screen or concrete wall in your case and mostly in mine, too. Concrete walls make great screens, often with nice horizontal mold markings on them that can be used for aiming purposes!

 

If you pull back some what does the beam pattern look like with the fog lights. I noticed when turning on the fog lights it doesn't provide a big difference in front and to the side of the car like they are suppose to. It seems the fog lights are just decorative. I could just change them out to something else I suppose and just use the wiring that is already there.

 

NoMoShocks,

Do you have a link to the Dan Stern site for the DRL-1? I'd like to read up on it and I couldn't find it. Also, where are you getting the HIR bulbs? What price?

 

Thanks for all the information. I ordered Yellow Xenon Fog Light Bulbs from Rally Lights (Susquehanna MotorSports). I believe fog lights s/b yellow.
I had them on several vehicles over the years and think they cut glare better, and give the driver more light than the white lights do.

May I inquire as to where you purchased your led signal mirrors from?

Thanks, Rob