Gaming the system: record EV range!

1. It will not require more than 1 gallon if the ICE is on higher thermal efficiency during the climb.
2. Faster downhill coast will take you farther not shorter.

Using regen (with its losses) is a bonus, using it at the end of the 50 miles improve total mpg. Regen also eliminate the extra wind resistance you are worrying about.

It is a P&G and can yield better mpg if done cleverly at the right speeds.

 

Sorry, but my example is not wacky. You can start and end at the same location. No laws of physics are violated and it isn't perpetual motion. If you actually read the experiments Newton conducted to come up with the basic laws, he does basically the same thing and concluded that horizontal and vertical components of motion were independent. The amount of horizontal distance covered has nothing to do with the vertical distance. But in computing mpg we are interested in the distance traveled.

Think about what you are saying. If a car gets 50 mpg on level ground and you drive up any constant grade hill that you can roll back down you cannot get 25 mpg or greater going up. Very easy to demonstrate this. Remember, I am saying nothing about the speed of travel.

Mike

 

ah HA! That may be why there seems to be a disagreement (i think). Yes, of course a hybrid, whether Plugin or standard, will get better mileage on flat ground when it P&G's. And if a similar car is going up hill... YES .... the Plugin too will get better mpg, using P&G, then if the pip had simply held a constant speed going up the hill. (For that matter, the downside of the Hill becomes irrelevant). If that's all that's being said, I understand & agree. Prior to that idea, it sounded like what was being said was that if you P&G a given distance (similar speeds) one trip on flat & another trip on a hill (averaging same speed) that returns to the same elevation ... the hilly trip would uses less energy (electricity & gas).
When comparing a plugin (Prius, volt, etc) becomes part of the comparison calculus, one has to also account for the battery'a preliminary charge as part of the energy use mix, offset by the additional battery weight difference between standard hybrid and plug-in.
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To clarify a bit more. I'm just saying that it is possible to drive on "some" hills and get better mpg than on flat ground. Not that every trip will or could be. Just that it is possible and that it breaks no laws of physics.

For example go up a constant grade that gets you 25 mpg. Turn around and coast down and you will net >50 mpg as you roll back past the starting point. Repeat the trip and take an alternative downhill path that has switch backs that is half as steep and twice as long. You will now net ~75 mpg. No P&G even necessary.

The Sonoma Prius Challenge was a bit like this. Uphill for the first ~1/3 of a lap and downhill for ~2/3rds.

Mike