Originally Posted By: inquirer
I am looking 100% for performance. I think color temperature could be counted as part of the performance equation. I have read that the best temp for the human eye is 4800K. At extreme values of temperature probably the drop in performance would be easily perceived by the driver, but of course temp is not that important as brightness, when temp values are average.
My car uses HB3 (9005) and HB4 (9006) bulbs. Are the 9011 HIR1 compatible? And are they road legal without any other modification needed?
The 9011 HIR1 and 9012 HIR2 (substitutes for each respectively) are ECE type-approved bulbs.
However, modification and use in an unintended application would no doubt render them technically non-legal.
My suggestion would be to do some research on the modification and suitability for retrofitting. There is a lighting forum (CPF) where the mods have credible knowledge, though they can be somewhat dogmatic and unforgiving in their manner. I would trust their recommendations over almost anything else, with few exceptions.
Overall, lighting and vision is a complex subject, and the level of understanding is poor among laypersons, not helped by the fact that human eyes make for poor photometric instruments.