Whitest Halogen DRL/High-Beam bulbs?
 

I recently replaced the headlights on my car with Morimoto M LED 2.0 projectors. These projectors are extremely powerful and produce a 6300k cool white color temperature. The problem is that the low-beam output on my car is now so white it makes the DRL/high-beam output look distinctively yellow.

I first got some generic 9005 LEDs and installed them in the DRL/high-beam sockets. I learned the FR-S uses PWM (pulse-width modulation) to control the light output of the DRL/high-beam bulbs so they can be dim in DRL mode and bright in high-beam mode. PWM does not work for LEDs, they always output at 100% intensity. Even though the 9005 LEDs very closely matched the color temperature of the Morimoto projectors, they were on at full intensity in both DRL and high-beam mode. This is essentially like driving around with your brights on all of the time during the day. I hate people that do this and I can't bring myself to drive around like that.

I found a single company, Xenon Depot, that claimed to have an LED and PWM driver that would dim the LED output to 12% when in DRL mode. This is not to be confused with all other LED PWM modules on the market that simply prevent flickering caused by PWM. The Xenon Depot kit was designed for the Toyota Tacoma, which has a similar PWM controlled DRL/high-beam setup as the FR-S. Xenon Depot support said their kit worked for most Toyotas, so I decided to give it a shot on my FR-S. The Xenon Depot kit worked fine on the passenger side, but the driver side flickered in DRL mode. I swapped everything to opposite sides of the car thinking maybe I had a bad LED or PWM driver, but the driver side still flickered in DRL mode and the passenger side still worked fine. I ended up returning the Xenon Depot kit.

Now, I have realized the only way to get functional DRL/high-beams is by using a normal halogen 9005 bulb. But, I still want to try and match the cool white 6300k color temperature of the Morimoto LED low-beams as closely as possible. I see there are many blue tinted halogen 9005 bulbs on the market that advertise outputting a very white color temperature (Philips Diamond Vision, OSRAM Cool Blue Boost, Sylvania SilverStar zXe, etc).

Does anyone have experience with these halogen bulbs that claim white color temperature output? What is everyone running for DRL/high-beams?

I bought Phillips Diamond Vision bulbs for my Fog Lights to match my LED Bar and HID Bulbs that run close to 5000K. The Phillips bulbs appear to run pretty close to 5000K but a touch warm, so I'd say around 4800K. Still a very nice white for a halogen.


See attached image. Left is the Phillips fog bulb. Right is a generic LED fog bulb. My HIDs are OSRAM Cool Blue Intense.


Will probably be challenging to find a halogen that peaks 6000K. You might try some of these options listed on this site, though color accuracy is unknown. At least you can get a feel for some options in the higher temperature range: https://www.bulbfacts.com/halogen-bulbs/chart/



The Phillips Diamond Vision bulbs were properly rated as far as wattage goes, but I noticed that they also put out a lot of energy in UV. They started to burn/smoke the Lamin-X covers I have on the fog lights. I would have kept them on if not for that. I put the LED bulbs I used to have in the fog lights back in for now.

I used to have Philips Diamond Vision on my DRL/high. When they're off, you'll definitely notice the blue tinge on the headlight. When on as DRL, they are white about 5500K but not as white as 6000K of LED's. Unfortunately, as of 2020, no one has made an LED halogen replacement that replicate the "dimmer" drl function (I've tried many brands like Diode Dynamics, GTR lighting, etc.).