check oil light on 2007 Toyota Prius

We recently went on a highway road trip and on the way back we ran bone dry of oil. Nobody at toyota can tell me where the oil went or why the oil idiot light did not come on warning low on oil, any ideas?

1 answer 1 comment
something is wrong. if you had no oil at highway speeds, your engine would be ruined. so there was "some" oil still
there. nothing will every take the place of old fashioned
oil dipsticks; the oil level light is NOT to be trusted,
thus the name "idiot light." sounds like somebody somewhere
did not refill the correct amount of oil at the last service; if there is no leak, where did it go?? quite possible it was not ever there!
I have been changing my own oil every 5000 miles for the last 80000 miles. The oil is almost always at alarmingly low levels. I put in 4 quarts and usually drain out 1 or 2. I cannot explain this either, I park on concrete and I have never noticed leaks. There is no oil buildup under the car. Something inside of my engine (150k miles) begins to rattle at high RPM when the oil level is low so when I hear that noise I add a 1/2 quart and it quiets down (frequently on long 500+ mile trips). I probably add 2 extra quarts per every 5000 miles. I have never seen any low oil indicator light nor a high temp indicator. I'm not surprised that someone may have run out of oil. I am not aware of any damage from this other than the rattle which does not seem to affect performance.