I've been driving in stop-start traffic recently. I could see the brake light by reflection on the car behind. I noticed that my foot could be lightly on the pedal with some braking effect before the light came on. So I wondered if I should have the brake switch adjusted so that the brake lights will come on at lower pedal pressure/travel and provide earlier warning to the driver behind. Now I'm wondering whether the tiny amount of braking, only slightly more that throttle-off regen, would be too much warning? So, what does the PC Brains Trust think?
Have you talked to a mechanic/dealer about adjusting this? I would imagine this offset you noticed is adjustable. This discussion reminds me of when I drive my manual shift car. Many times I slow the car by downshifting. Many times, this is not a subtle reduction in speed. Of course, if someone is not paying attention, or following too closely, they may collide with my rear bumper. I just need to be conscious of the driver behind me, and how they appear to be following me. Sometimes you can't do anything about a person who is tailgating you, other than pulling over and letting them pass.
I imagine that the switch is adjustable; some type of screw and lock-nut arrangement. I was considering stop-start traffic only since everywhere else I Drive Without Braking (DWB) and drive smoothly. It's where traffic is lumping along that I want to give the right signal to help the drivers behind me. Your point about down-shifting is just the type of counter-argument I was thinking of. The first "bite" of braking on the Prius is somewhat more subtle than dropping a cog. I know that the VW Golf EV prototype had 3 levels of regen and the brake lights come on at the highest level 3. (I don't know if this carried through to production.) The Mitsubishi Outlander PHEV has 5 levels (or 6 if you count zero) but I haven't confirmed its brake light situation. B5 on the PHEV is a double-down-shift without the clutch. It makes sense that if deceleration, whether by foot brake or by regen, is above a certain threshold, the brake lights should come on. If regen levels were selectable I would probably use the highest level in stop-start traffic and modulate it using the accelerator. In that scenario I'd want the brake lights to come on. (BTW I'm assuming that active auto-braking would be ineffective/disabled in low-speed, stop-start traffic and I don't have it anyway.)
