Thanks, Don R, for the explanation. It sounds like I was trying to do a little too much and should leave much of the MPG increase specifics to the engineers who programmed the car. In other words, just having a light foot, looking ahead, and driving conservatively should do a lot. Next progression would be pulse and glide?

I've been playing with electric-only at low speeds... in my 400h, it's useless at anything outside of my cul-de-sac. I have about 70% full battery, drove maybe 1 mile at electric only, and in addition to it taking 20 seconds to hit 20 mph, it nearly emptied the battery. This doesn't seem efficient to me considering how long it takes to recharge that much battery power.

You're right - it's not at all efficient used that way, and wasn't designed to be due to limited battery capacity. It's a big mistake trying to run in EV mode as much as possible and depleting your battery quickly unless you have predictable downhill braking runs to regenerate. Without this, the ICE has to recharge the traction battey at an efficiency of probably around 20% (ICE efficiency of about 30% times mechanical generator efficiency of about 70%).

Accelerating modestly with the ICE to just over target speed and then gliding in EV mode is much more efficient, with brief computer-determined motor boosts - using both in their most efficient modes. Anytime you try to accelerate in EV mode is just a killer of the traction battery as you've found out.

The only free lunch in hybrids is in braking regen mode, which is what they are all about, allowing accessories to keep running independant of the ICE. Don't waste this on acceleration trying to do what the ICE does much better, and more efficiently.

Things WILL change to what you wish you had now in a few years when battery capacity grows by quantum leaps and every car is a plug-in with a much smaller ICE.

Pete

My good EV runs are conviently broken up by either an occational hill or higher speed areas. Using the battery on the flats, I usually run if fairly dry, but this I get to an area where ICE is pretty much necessary & I get a recharge, usually just in time to start me next <=40mph flat.

I'm actually seeing speeds of between 42/44 before ICE is mandatory, but the closer I get to this point the less chance of even holding speed on electric alone.