I would guess that the hi beam is just a bigger opening for the HID setup (the Acura TL uses this setup..when you turn on the hi beams, you can actually hear the mechanicals working...) if this is the case, its great because then you have a true bi-hid setup with hid high beams too... personally, I prefer the parking lights, takes me back to the good old days of cruising on summer evenings with parking lights on...