2.5x - Hmmm ...
According to Oregon.gov:
:
" Auxiliary driving lights and/or fog lights must be used like the high beam headlight system of your car. You must use a distribution of light or composite beam so aimed that the glaring rays are not projected into the eyes of the oncoming driver. Fog lights may be either white or amber (yellow). They may not be blue, bluish or any other color than white or amber.
Oregon Revised Statute (ORS 811.515 Section (8) states: A light other than a headlight, that projects a beam of light of an intensity greater than 300 candle power shall not be operated on a vehicle: (b) when use of low beams of the vehicle headlight system is required under limited visibility conditions.
(So if you need lighting, you also need your low beams on in Oregon - No mention of tail lights in the statutes - but no specific prevention of fogs as DRL's)
ORS 801.325 "Limited visibility conditions means: (1) Any time from sunset to sunrise; and (2) Any other time when, due to insufficient light or unfavorable atmospheric conditions, persons and vehicles are not clearly discernible on a straight, level, unlighted highway at a distance of 1,000 feet ahead."
To me, this means if you are using your fogs because you need them, you also need your low beams on.
If you use fogs as headlights at night, you can be cited, and the fact that you have not means you have not, not that you can or should.
If you are talking about using them during the day as DRL's it should be okay in OR or other states when visibility is NOT an issue, but like you said, in some states local laws make it a violation to use fogs anytime when it isn't foggy. In Oregon, at night fogs are considered to be "high beam" lights, even though they aren't.
For the OP, that scenario doesn't apply, because he is talking about using them at night (not on the road in his case so the law doesn't apply).