Does Gas engine run too much ??

Don't expect to be driving around town on the electric motor all the time. The car doesn't work that way.

In reality, if the engine is warmed up, you can manage to maintain electric only driving only with the lightest touch of the gas pedal. It's suitable only for moving up a car length at a time in a traffic jam.

As soon as you attempt even moderate acceleration, the gas engine will turn on. This is the way everyone's Prius works. (Well almost everyone, since some people have installed a switch that forces it to remain in electric mode, but you can't go far like that).

You will find, however, that the Prius will readily use the electric motors to maintain speed on flat roads when traveling under 42 mph. However it still takes a somewhat light touch of the gas pedal to accomplish this.

When the A/C is on, the Prius seems to be less willing to run on electric only.

 

I see a different change... When the AC in set at a low temperature (67F) the gas engine does not run as often as when my girlfriend rides with me and sets the cabin temperature to sweltering desert (79F).

Around here, at this time of year, if I set the cabin temp to 73F and stay stopped at a light, the gas ICE will come on. As soon as the ICE is running, I'll adjust the temp to ~70F and the ICE will shut right off.

Try adjusting your temperature to find out where the ICE shuts off. You can sacrifice comfort for efficiency.

 

Marlin's reply to this question is very clear and helpful and should be handed to all new owners!