Since I live literally next to the freeway, would it be a problem if I accelerated to 65 on a cold engine right from the start? Keep in mind this is an older Prius and my apartment exit is adjacent to the nearest freeway onramp.
Will it do it? Yes. Is it bad for longevity of the engine and the battery compared to a gentle warmup? Yes. I would say give it at least the ~50 seconds to leave stage 1 before going up the ramp. If you do that as habit, but occasionally go straight up the ramp if you are in a hurry, it's not going to make much difference.
If it's at all practical, drive to the next on-ramp before entering the freeway. A few extra minutes warmup while driving gently will help your engine life.
Living in southern CA, your definition of "cold" is a complete non-issue. I live in MN, where it gets drastically colder... and never had any trouble, despite also living next to a highway. Even when seeing this: .
i know i own a genII... and this is for a genI... i tow with my genII... to the point that if it's warm out or if i'm going N instead of S with a small incline it will partly drain the battery since the car uses mainly electricity to run during stage 1. as Flaninacupboard said... a warmup isn't all the bad. any time i do a warmup on my genII... my gas mileage is more predictable and i always have a more stable battery when i do a warmup. yes.. it may pollute more sitting there for warmup... but a person smoking a cigarette (possibly me) probably does more damage to the earth than a simple warmup (gross comparison... but really.. it doesn't seem all that bad to do a warmup)
I have a 2002 Prius and I also wonder what you consider "cold" in CA being in MN. I have driven the 2002 in -25F weather and there is a blue light that corresponds to a cold hybrid battery and I believe that while that blue light is on you're supposed to take it somewhat easy? I also saw the neffarious "turtle" light one cold morning - but only once- which ironically appeared after a full hour warm-up on one of those sub-arctic mornings which is supposed to indicate a battery that is overheated ?? and you are supposed to drive under 30 mph until the turtle goes away.
