250mpg on how steep of a downgrade, and for how short a distance?

Look, a gallon of gasoline will release a certain amount of energy (as heat) from oxidation. You can apply that heat to a UFO and not get 250 miles.

Gyroscopic effect is an enormous factor with flywheels, and gyroscopic effect produces mechanical (mass) stability proportional to the energy stored in the flywheel. Using a gyroscope (which you/we are calling a flywheel) to directly propel a maneuverable vehicle is not possible. Yes, remember that we are interested in maneuverable mass-producable, passenger, highway vehicles here. That means roads, tires, turns, pavement, the presence of other people and vehicles, and points of origin and destination.

Certainly flywheels are useful components in our vehicles, but such exaggerated claims are what have hurt the pursuit of alternate energy for far too long.

 

I appreciate the sentiment behind your post and I would be the first to admit that nothing should be said that could damage the credibility of alternate energy technology. That said, it must be noted that my post has been based on practical figures and facts. Please note that a car has already been produced that gives not just 250 mpg but an amazing 300 mpg see: This article: Also your statement that it is not possible to produce a maneuverable vehicle in which a flywheel is employed for motivating power is also wrong. Vehicles using this system were in use for eight years at various places around the world. See here :

 

I'm not here to argue or be a naysayer. I'm in favor of hybrid vehicles, in the fullest sense; not purely dependant on one type of fuel or energy store.

I'm here looking for practicality though, and I'm only one of many such people. I'm put off very much by exaggerations and excuses. I ask others to be open, realistic, precise, and problem solving. There are plenty of sci-fi websites.

So far one fact I've seen established quite firmly here is that MPG is a term only as good as the one who uses it, and qualifiers must be looked for carefully, beyond the plenty of evident ones.

 

A flywheel is a mechanical energy storage device. It requires mass, and when energized posesses mechanical angular stability. Both of those traits are at odds with mobility and maneuverability. I didn't discover or write the laws of physics, you can learn them too!

For a flywheel to provide any benefit for the propulsion of a vehicle, it must be energized by a source that is so much more efficient than the alternate power source as to offset all the losses in its energy transfer chain.

Incidentally, the statement I made earlier: "Using a gyroscope (which you/we are calling a flywheel) to directly propel a maneuverable vehicle is not possible." is accurate.