You can't drive only in electric mode, because it needs to run the engine to charge the battery. Typically you need to drive for a while until the engine is warm and the battery shows 6 bars or more. Once the Prius is warmed up and the state of charge is suitable, then just get up to a speed of 35+ MPH and then release the accelerator for a second then reapply accelerator pressure very gently and the energy monitor should show you running on electric only. It's best to do this on flats or slight downhill. You can run in electric mode with less than 6 bars, but the fewer bars you have then the more difficult it is to keep it in electric mode. To get to more than 6 bars you usually have to travel down one or more hills, though you can also get there by decelerating from high speed.
(Continued ....) You can also glide from speeds less than 35 MPH, but you have to know how to get into "hybrid stage 4" first. You can get into "hybrid stage 4", after the Prius is warmed up, by allowing the Prius to sit at rest and idle the engine for 7 to 10 seconds (until the engine cuts out).
For the GenII design, coolant must warm up to a temperature of 145°F before the engine will shut off. At that point, you'll be able to drive at a speed up to 42 MPH until the electricity supply for that runs out. On the display for the battery, that's the pink-level (2 bars). Keep in mind that maximizing electric-only driving is the most efficient choice, since the engine must recharge afterward. There is clearly a MPG benefit at times though. Discovering when is part of the Prius ownership experience. Enjoy!
Vanne, Read this The Five Stages of Prius Hybrid Operation | PriusChat and this http://www.cleanmpg.com/forums/showthread.php?t=1224 It helped me a lot.
Vanne, I definitely recommend you to take the time to read "The Five Stages of Prius Hybrid Operation". Also, do a google search on "pulse and glide" without the quotation marks. When you understand the five stages of how the Prius operates and learn how to pulse and glide, you will then appreciate more of the value and mileage of the Prius. I would not recommend you try to drive it all the time in "electric drive" (golf cart mode). You will end up using the gas engine more than you would if you were to pulse and glide. Whatever you use on electric will sooner or later be replaced by running the gas engine. If you appreciate my post's and value the information, please consider clicking like on this post. Ron
