How often to drain gas tank when only using EV mode

How about seals and gaskets? Don’t they need to be lubricated to prevent oil leaks?
Maybe apples to oranges but I had a spare submersible sump pump I never ran for years until I heard you should run it periodically to keep the seal lubricated. I ran it for a minute and it leaked oil badly. I run the replacement for a short while every few months. No leaks.

 

On top of that, I understand that the Prius spins the engine faster during startup than a gasser and doesn't fire up the ignition & fuel till it has oil pressure, so no load on the bearings till there's oil pressure. That would greatly reduce cold start friction and wear.

 

It must do all of that in a sub second timeframe because my Prime and previous Gen 2 started the engine almost instantly. I get the spin up but how much oil pressure and oil distribution could happen in that short a period of time? I’d like it to be true but how can one actually prove it?
That said I run the ICE weekly “Just because” it gives me a warm fuzzy feeling. I just push the HV button once, wait for the ICE to start and then press the HV button again. The ICE then continues to run for a minute or three depending on what the outside temp was at the time.

 

I'd be inclined to have a "hybrid vehicle" day, at least once a week.

 

I'm not sure how long it takes, but it can't be more than a second. And it's pretty hard to tell if the engine is cranking or running from the tales I've read here of people thinking their Prius starts for a couple seconds and stops when it's actually cranking, not starting, and timing out.

 

My ICE is definitely not just cranking. I can hear the increased engine sound whenI accelerate.

 

I heard running the engine for too short a time could cause moisture to build up, which is normally expelled when the engine is usually brought up to operating temperature (197F?) with a longer run.

 

This is true.
And the "procedure" you replied to is likely WORSE than just letting it sit......for several reasons.