"
Wow. You still don't get it"
Nope...and neither does GM...which is why they created
'Mountain Mode'
Why does the Volt have this mode?
First lets look at the gas engine, which is less powerful than a Festiva....and compare it to the Volt's weight, which is heavier than a Crown Victoria. Without help from an electric motor, the gas engine would give you the performance of a riding lawn mower.
So, they created the buffer in the battery. You want to accelerate, pass, go up an on-ramp, go on a sustained grade, turn on the wipers...you'll dip into the buffer. And GM figures that statistically you'll hit enough downhills and brake at enough stoplights to keep the buffer (30% charge) sustained....under
'normal driving conditions'.
What about
'not normal' driving conditions - Loveland Pass, Dallas during rush hour, alot of merging, ramps, passing, etc? This will deplete the buffer much faster than the gas engine can replenish it. So, they came up with 'Mountain Mode' (I guess the guys who designed the car 'just don't get it'

). Essentially you change the time and place for poor driving performance. You have to anticipate that you will encounter tough conditions, and switch the mode on around 20 minutes prior (just one of the awesome things which I'm sure will make consumers fall in love with the car). Now your ability to accelerate or climb grades is severely diminished...you're in 'granny mode'...but it allows the battery charge to increase from 30% to 50%. Now, you have an extra reserve to make it through the pass....their estimation is it will give you 14 miles normal driving, and less tough driving, before depleting back down to 30%.
Why doesn't GM 'get it' and assume that the ICE can magically recharge the battery all the time? They know what I know -
the Illuminati closed down the magic fairy dust mines in the '80's. 
There are losses in converting mechanical energy to electrical energy, storing said electrical energy in a battery as potential energy, retrieving said potential energy as kinetic electrical energy, and converting said electrical energy to mechanical energy. How much? I can't calculate it...but GM has. At 70 mph, the gas engine starts to directly drive the wheels to some extent....so this is their breakover. Does it take less than 83 hp to keep a car going 100 mph? You bet. Does it take less than 83 hp to convert mechanical to electrical to potential to kinetic to mechanical and sustain 100 mph...no!
So back to the initial subject of the poor gas mileage of the vehicle. I still confidently guarantee that the poor gas mileage was
NOT because anybody was attempting to charge the battery, as previously alleged. The car is not even programmed to do that...and if it were, you would either need to coast down Mt Everest, or do a 30 mph loop around the Utah Salt flats for around 90 minutes. Neither Edmunds or Consumer reports mentioned calling in GM for the reprogramming, or the trip up the north face, so I assume they got their lousy mileage...well, just driving the vehicle like normal.
For those who have made it this far, we have almost touched on the real difference between the Volt and the Prius.
Prius - Gas engine capable of powering the car in all conditions. Small battery to recapture some of the lost energy during driving, used to supplement the engine.
Volt - Large battery and electric motor, capable of powering the car in all conditions. Small engine used to recharge the battery....under some conditions.
Which system works better? The Prius. The jean creamer for the Volt evangalists has been the plug in range and electric drive. Well, Prius will plug in next year...and the manic Voltecs will scream "You see, Volt is better"...but they won't understand (err...'get it'). Prius will still have the big engine/small battery concept...they will just squeeze out a few miles from the initial charge, using their small battery...knowing that to reverse the setup to that of the Volt's is not nearly as efficient.
Even advancements in battery technology won't make the Volt the better system..because the Prius would benefit equally from that improvement. In order for the car to drive normally, you always (really...all the time, always) have to have enough power to well, drive normally. The only (really, I'm sure) way to always have enough power is carry on-board fuel for the
primary powerplant. This could be natural gas, diesel, gasoline, hydrogen...or even a battery. However, all of these fuels need to be re-filled.....easy to do...
except for the battery. This is why the 'normal' driving experience for a Volt is limited to its plug in range. After that, its really not a normal, everyday driving experience. It never will be...it never can be.....unless the gas engine has a hp rating much higher than the rated max output of the electric motor.
Physics....catch it!