High beam question

Swapped better hi beam and lo beam bulbs in my 2017 TRD Sport and when checking their operation (parked in the driveway, motor running, parking brake set) noticed that when high beam is selected the lo beams stay on. Never noticed this before. Checked the owner's manual and no help. 2017 with projector lo beams are totally different from my 2007 TRD Sport. Am I missing something in "settings" or is this a safety upgrade? Did a search in the forums but did not find any info. Stumped. Appreciate any clarification. Thanx in advance.

 

Normal. 3rd Gens have separate high and low bulbs, allowing both to run simultaneously when using high beam. 2nd Gen has a single dual filament bulb (H4) that will quickly overheat if running both filaments at once, so only one filament is run at a time.

 

You're the perfect person to answer, lol.

 

Thank you for the quick response. Appreciate the clarification.. The posts with info and tech data regarding headlights especially bulb recommendations have been very informative. Your in-depth analysis of the headlight problem/shortfalls made selection much easier instead of sorting thru the mfr hype and marketing promises. Driving at night with the recommended bulbs will make driving the country roads much safer. Thanx again.