Due to environmental considerations, I am planning to purchase a plug-in hybrid electric vehicle when the vehicle I want becomes available (RAV4 Prime). However, I am concerned of the gasoline in the tank going stale. I have the possibility to charge the car at both home and work. So, given the 60 kilometer range, I don't believe I have to drive on gasoline except perhaps two times per year. I mainly do short trips.
I'm worried of two things:
If the car always prefers electricity given enough charge in the battery, I can end up having the same gas in the gas tank for a year or two. I have understood that gas eventually goes stale.
If the car has a system to automatically use some amount of gas occasionally, even if you always charge the car, the gasoline consumption can actually be pretty high, so the car doesn't deliver the gasoline usage savings I'm expecting. Example: 56 liter tank, 2 month turnaround, 336 liters / year used (ok, I guess that's better than 1300 liters / year I'm currently using).
Are my worries real? How do plug-in hybrid electric vehicles handle gas going stale in the gas tank? How quickly does the gas actually go stale?