So I drove from work to a local gas station just around the block, around 1-2 minute drive. After filling up, I could tell that my engine had not fully warmed up. I then proceeded to turn onto the feeder and accelerate up the ramp to the highway to around 60-65mph. During this acceleration I stayed in the ECO zone, though I filled it up close to all the way. I then noticed something peculiar: I was getting 75+MPG. I then noticed that the engine was noticeably quieter. It was then I saw the battery drop in power at a really fast rate (5 bars to 2 bars in 30 seconds) before the car started to act normal again. (It probably saw the battery was depleted). Although I have noticed this behavior before when the engine is cold (it seems to rely only on the electric motor if you accelerate gently enough), I have never seen the electric motor used to such an extent to such a fast speed. I guess I also see why Toyota capped EV mode to 25mph, though clearly the car is capable of more. This interesting event also gave me an unexpected possible preview of how well a plug-in Prius could perform. Acceleration was definitely acceptable, and maybe it could have actually gone a little faster (I didn't push it into the red zone after I noticed this behavior). I also hope then the plug-in Prius will be able to operate more like in this situation and not just during cold engine situations (due to the Li-On battery). It does also show that part of the puzzle for a plug-in version is already in our Priuses. If someone developed 3rd-party LiON batteries for the PlugIn Prius, I can definitely see it getting around town, highway acceleration and all, with insanely good mileage.
I have noticed that the Gen 3 uses the battery a lot more often than the Gen 2. With the Gen 2, I know if I give it a quick burst, it will spin up the engine but on the Gen 3, it will still use the battery to propel the car unless I really go for it. I've also noticed that the battery recharges a lot quicker (either via regen or engine charging).
My guess is you were in the Stage-1a of the warm-up cycle. http://priuschat.com/forums/gen-iii-2010-prius-fuel-economy/69393-warm-up-time-3.html#post969771 Ken@Japan
Agree w/Ken. In the Gen II the car will "try" very had to keep the RPM of the ICE to about 1275rpm while putting a much heavier draw on the battery while the emissions control systems are warming and the ICE is warming. Apparently the Gen III is even more aggressive in this regard.
