I am a safety representative and truck driver and we have @ 40 newer Kenworths where I work. We have recently started a night shift and have been having driver issues regarding headlights. Of course management wants to do the right thing but as always are concerned about cost. Has anyone here tested the various brands and types of sealed beams out there already? Is it a fact that sealed beams lose their brightness after awhile?( say a few months to a year?) Thanks for any input