Got a chance to try this today... I left the parking lot today with two bars SOC and the engine was on for maybe 1.5 - 2 minutes and I gunned it to make a light. The car picked right up and so did the engine rpms. I didn't have an SG on it but I would have to say it was (rpms) were somewhere in the mid range.
Prius acts completely different animal between the first 57 seconds stage-1a and the following stage-1b. Ken@Japan
(sigh) same traction pack / mg1/mg2. Of COURSE the hardware has to be modded to allow for this. You're still missing the point. The existing electric power supply and hp deliverable from the prius IS sufficient to take it up to 60mph. Thus, while warming from 1a - 1b and beyond, the Prius (with retarded timing) WILL use more electric motor power to proceed through early warm up. If THAT makes you scratch your head, consider this: If your traction pack is pulled all the way down so that NO bars show on the MFD (blank traction pact icon), your ICE will REALLY have a conniption. Take off cold in THAT scenerio and you'll REALLY hear your ICE whine, as it's trying hard to do regen, and having to deal with retarded timing. Now, to answer the OP's thread title regarding (my 5yr average) actual cold mpg's: 40-49 degree f. per tank 57mpg 30-39 degree f. per tank 50mpg 20-29 degree f. per tank 46mpg 10-19 degree f. per tank 44mpg . Haven't ever done a full tank with lower temps, but the above represent at least 2 tanks during (at mostly) those temps. I'm certain that most folks will do worse, as these results are with practice, an EBH, extra warm thermostat (thank you Ken) and grill blocking. I'd rather focus on nice temps: but that's for another thread .