Doesn't the 2009-2010 Corolla have auto-on headlights? That makes it even more inexcusable, but maybe that also makes it a bit more likely that Toyota can add it to the Prius.
There is some history behind this question. The auto-on feature is not used with HID headlamps, as HIDs suffer when switched on and off repeatedly (which can happen with auto headlamps). In the U.S. market, the more expensive Gen II Prius were shipped with HIDs, so no auto-on. I assume the feature was left off on the cheaper packages as it would be inconsistent to include a feature on a cheaper package and not have it on the expensive packages. In some other markets, auto-on headlamps were standard. You can see where the auto-on sensor mounts on the dash next to the solar radiation heat sensor. On U.S. models there is a blank in this spot. Tom
Interesting, but how many other cars with HIDs have auto-on lights and HIDs without problems? I can't think of another car that had HIDs and didn't have auto-on lights. They could set the sensitivity so there is a longer delay before they are triggered to turn on automatically. Why was this not an issue for the Prius outside the US? No HIDs on 2010 anyway.
I confess I am a bit confused, I turned the headlights on when I took delivery of my 09 and I have never turned them off. They come on when I start the car and go off when I leave the car. My previous car was a Subaru with ignition controlled headlights and I made sure the Prius had this feature before I purchased it. Day, Night, Underpasses, Garage, my headlight are on. Some one may stress over the 0.3 MPG loss, but I am happy being seen by my fellow drivers.
One problem is that nav users would then lose the automatic switch over from day to night mode screen if the headlights are on all the time rather than turning on automatically in the dark. It is a cascade of annoyances that would be solved with automatic lights.
My Japanese market Gen II Prius (July 2008) has HIDs and an "automatic" setting for the light switch, which is how I always leave it. It switches on and off based on the light sensor near the windscreen. At night it comes on when I start the car, a daytime it doesn't.
My BMW with HIDs has the auto. In fact, they made it super quick and sensitive so that they DO turn on in tunnels, garages... ect.. They haven't seemed to endure any more wear. Though I would cringe a little bit when I pulled into MY garage and seen them click on, only to be turned off. They also had the "pathway lighting" which required you to pull the stock and reactivate them after you turned the car off. So, they obviously don't think that those instances are enough to really impact them.
Oh, and I got a response from the Toyota channel on youtube saying that the Prius does have auto on/off.. Well duh, but that's if you wanted to leave them on all the time. THAT will cause HIDs to reach their half life quicker, and therefore making them more dim. Of course, if you don't mind switching the bulbs it's an ok option. They last so long, that the $70 bulbs aren't terrible. (Gotta shop for a good price though.) It WAS however really annoying and hard to switch the bulbs in gen2, even with my small hands. What I wonder is if the LED lights don't dim out and if they have such a ridiculous life span that it would be perfectly fine to leave them on.
Leaving the light on all the time will have annoying issues with the interior instrument panel lights and the nav screen not switching between day an night mode. This is not a good substitute for auto-on lights with light sensor. I can't believe the 2010 Prius doesn't have this. I think cars from olden times has a feature called "Twilight Sentinel" that did this.
I agree that it makes no sense for Toyota not to have the auto-on lights. My insurance company, Geico, will not give me the discount for "auto-on lights" because my 2008 Prius doesn't have it. Even if I tell them I will leave the lights on all the time, it doesn't matter to the insurance company. The car model has to specify "auto-on lights" or no discount. 'Silly and infuriating.
Toyota could even take it a step further and make the Prius the first car where the headlights turn on automatically when you have the windshield wipers on. Some states require headlights on with windshield wipers.
After noticing that the 2010 Prius has White colored parking lights mounted high in the top of the headlights, I started wondering if Toyota uses those for the Daytime Running Lights in Canada and there might be a simple conversion or firmware setting. Can a Canadian comment? It seems all one needs to do it leave the parking lights on all the time. When you shut the car off, they will turn off in 15 seconds. The tail lights would be on too. Would that be a bad thing? If you wanted to be sure they would not be turned off, you could install a jumper to short the Parking Light circuit in the light switch.
I'm also baffled why the Gen IIIs haven't added auto-on. I got very used to this feature on my BMW. Odd to have to remember to turn on lights. And I did see a Gen II last night without lights on.
FYI... the new Nissan Cube has auto-on headlights in some of their models. The reason I mention this is that the Nissan Cube is a very inexpensive vehicle. I am certain that cost was not a consideration as to why it is lacking in the Prius.
The two most expensive Dutch versions do have auto on LED headlights. However I don't know what that means. Maybe the car has a sensor that switches the lights on when it gets too dark, or the headlights will be on as soon as you start the car. We use the headlights as DLRs (not the high beam of course). I read soem comments about the nav system switching to night mode when you switch the headlights on. There is no reason for that, a nav system can calculate when the sun comes up or goes down.
Does the nav actually change mode based on time or does it change mode based on the status of the headlights? I know portable navs change based on the time of day, but what about the 2010 Prius? I thought it also had something to do with how the brightness setting of the instrument panel lights which is another setting to keep fidgeting with between day and night if you leave the lights on all the time.
