San Antonio man has engine that gets 100 mpg


**We’ve heard rumors for years about engines capable of getting 100 miles to a gallon of fuel, but the reality is much closer than you might think. Josh “Mac” MacDowell says he not only has the engine, he has come up with an idea, strong enough the U.S. patent office has given him a patent for it. MacDowell is using a Stirling engine, coupled with thermopile technology to make it possible to drive a Hybrid electric car and never have to stop to charge it.

The Stirling engine was actually invented 200 years ago, in 1816. The engine is driven by the exchange of hot and cold air, much like nature drives a thunderstorm. The Stirling engine is capable of using roughly 50% of the energy it produces. An internal combustion engine, like the ones in our vehicles, uses about 14%.**

The article continues at the link.

Also, I’d like to apologize in advance if anyone finds this article personally offensive.


He might want to create a working automobile with this engine before he makes public claims about its performance.


Filing the paperwork for a patent is a long way from having a production ready engine. It would be great it if happened, but I wouldn’t hold my breath. Read some back issues of the IEEE or MIT magazines. Just about every issue they talk about some new technology that will change everything that never gets beyond the prototype stage.


It’s kind of funny that you say that, because it shows on a certain level how conscious we are of news media’s phoniness. You know, it is possible that since Texas A&M University is involved, that news leaked out that way. And also, he did obtain a patent, which is public information that’s exceedingly easy (and fun) to find online. So, we should at least consider the remote possibility that mass media journalists do occasionally do their job correctly. In other words, it isn’t necessarily an infomercial. It’s funny on another level, too, because people are virtually never capable of spotting the trillion dollar a year oil industry’s constant, aggressive practice of using public relations firms to plant articles in the various forms of news media. Those articles are taken as Gospel truth because they’re so slickly and professionally manufactured, whereas some random inventor will just come across as some scamming salesman.


I agree that this will likely never see the light of day, but we might disagree on the reasons why.


Whatever happens will happen. I have magazines going back to the 1950s that made incredible claims about ‘how to get more mileage out of your car,’ but nothing further. So, whatever happened also happened back then.



Post it to the internet and we can all build copies.

Reminds me of a guy who bought a device that improved gasoline mileage by 20%. Every ten miles he has to stop and let the excess gasoline pour out of the gas tank.

But in all seriousness, I purchased one [Stirling Engine] and it sits on top of my wood burning stove. It takes heat from the top of the stove and converts it to energy to cause a fan to spin and circulate the hot air. It’s excellent.


Let him show me his engine in a car with 4 adult passengers, 300 lb of luggage, cruising at 70 mph with the air conditioning running, and still getting 100 mpg. Until then, it’s just a useless gimmick.


These Engines that can be extremly economical to run have been created over the decades, only thing wrong is, they get bought out by huge oil companies ,then locked away never to see the light of day, plus Government are no real help either,because of where they get financial contributions ,


US patents only last 20 years. There’s nothing preventing you from building the engine yourself, selling it and making yourself a mint. Other than,of course being willing to risk an enormous amount of money and time to try to being to market an engine that may not be technically viable.


Urban legend.


And then Atlas Shrugged.


Please post it … please.

Many of us have home basement / garage workshops and can fabricate engines from raw steel.

Please post the design.

As a side note, Jay Leno is now in his second season with “Jay Leno’s Garage”.


And he visits people who DO BUILD THEIR OWN ENGINES.

So please, please, please, post the design.

In a recent program, he visited with students who built their own cars and participated in competitions.

So, please please post the design(s).


How long will the car that uses this need to sit there before it comes up to operating temperature, especially in winter? Is the car less efficient in the summer when the ambient temperature is warmer?


I was about to click on the link, but your last comment stopped me – why would this article possibly be personally offensive? Is it NSFW?


Nah, it’s not the link. I said something stupid in another thread about oil companies having a vested interest in cruddy gas-guzzling engines, and somebody got angry. As well they should have, I guess. :shrug: I don’t know. I was just taken by surprise over how emotional this topic can be.

The link’s safe and innocent. If it didn’t involve a major US university I wouldn’t have even posted it.


Seems to me that people may have taken exception to what appeared to be a false accusation.

If the accusation or claim is false then what is the purpose of making it?


Still waiting to see if this pans out.
But have my doubts.


It sounds like it’s a regular diesel generator that also uses a sterling engine to convert radiated heat energy into electricity.


Smokey Yunick had a Pontiac Fiero that operated at 80% efficiency, got 51 mpg, and developed 1.8 hp per cubic inch.

Original article from 1984 in Hot Rod:

What it’s like to drive:

Nobody knew how to get more out of a car than Smokey.

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