probably BS. All patents can be researched. If there was such a U.S. patent, it would be widely linked to in conspiracy web pages. There are probably electric car patents bought up, then never produced by a car manufacturer. A premise that doesn't need a conspiracy to explain. Given it's smart business sense to buy up emerging tech to use it yourself. With the obvious downside of finding out the hard way that a tech doesn't pan out as easily as anticipated and get scrapped.
i.e. person patents electric car variant. Auto exec sees this and thinks "we could make a lot of money on this!" board meeting happens, choice is made to invest in it. Patent gets purchased, experimentation gets done, Problems get found, logistics snag up prototype production, project gets scrapped. Result: Car company gets accused of suppressing tech. they "don't want out"
There are ALWAYS other solutions that don't require a big conspiracy. Occums razor: The simplest solution is usually the correct one. And in this case, the simplest solution is that things are harder in reality then theory. A problem that anyone who has tried to produce any invention has come across.
There are often cars that a manufacturer starts production on that never reach a finished product. I remember wondering when the "Jeep Icon" would be produced, then finding out it was canceled after coming across press releases about it. And this "concept car" is one of a multitude.
Occam's razor - Wikipedia, the free encyclopedia
A recent innovation: Someone has invented an engine, really just a slightly modified one that runs partly on water to extend the distance you can travel with it. The method it works is after the engine is nice and hot, you spray in water into the hot cylinder. Every X number of cycles it's water instead of gas. The heat generated flash boils the water to steam, giving you some power, and it's just getting energy back out of the heat that the engine normally has to expend energy to eliminate. With a modified cooling system it was able to increase gas mileage by 40% I think. (could be wrong on the percentage) This engine hasn't made it to production, due to the rather obvious problems of increased wear and tear on the cylinders. After all, over time, guess what water does to steel? Even stainless steels don't resist corrosion as well at higher temps, and higher wear situations. This problem could be overcome by more and more expensive alloys of stainless steel. End result: to make the engine viable and last long enough to be of practical use required making the engine alone cost far too much to make it viable in a car for the prices people would be willing to pay.
As a side note, Hydrogen storage problems is what convinced NASA to scrap the X-33 project. (i.e. the venturestar program, supposed to replace the space shuttles) A company here in utah trying to make a lightweight tank lining that could increase efficiency enough to make the project viable failed, badly. Without a lightweight tank, enough efficiency to make the design work was unavailable, and NASA simple stuck with the existing space shuttle fleet. using heavy external tanks that must be dropped off to complete the flight. The storage can be done, but there are so many problems to overcome before lightweight storage containers are build. Keep in mind weight on a car effects efficiency....
