Interesting. Still seems odd to have three designations, but I figured it had to do with evolving standards.
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Yes, I lost both low beams on my '99 Camry. I knew as soon as I left work that something was amiss, as the DRL's use low beam at full intensity 100% of the time. [DRL's on with engine, even in park. Some day I might fix that.] I stopped and verified that I had the parking lamps (yes), and rear brakes (yes), and high beam (yes). Looked in the manual, saw that I had four fuses, pulled left low beam; it was fine. Was running late so I went with it. Thankfully my lights are aligned low so I didn't annoy too many people (someone replaced before I bought, and I've been slowly aligning them).
This morning I pulled both bulbs, and left low is blown. Right low looks fine... so no idea why it quit. Picked up a pair of cheapo Sylvania Walmart specials this morning to see if it restores operation, or if I have something else amiss. [Probably will order some Osram Silverstars, last I knew they were the good things to have--either these will work "good enough" or they will be relegated to spares.] [Drove the truck today, as I needed headlights this morning, and will definitely need them tonight.]
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Too bad I gave all my H4's to the guy who bought my Jetta. Too bad my '11 Camry has to take yet a different bulb!