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by hugh4 3658 days ago
An engine doesn't get 100 mpg, a vehicle does.

Attach it to a normal-sized vehicle and get 100 mpg under realistic driving conditions, and I'll be impressed. ('til then I'll be internet-snarky!)

2 comments

The fifth paragraph addresses the significance of your point.

I'm skeptical, but I applaud him for making public a very specific and short-term goal that we can all watch: coast-to-coast USA on 40 gallons of fuel in a small SUV.

>> coast-to-coast USA on 40 gallons of fuel in a small SUV

Without having a source, I suspect a caveat wherein he will plug in to fully recharge the electric battery every X hours, which would be far less impressive.

Now, if this is cross-country, on a single 40 gallon tank, without plugging in to recharge, in an SUV that is not gutted to reduce the vehicle's weight... that would be impressive.

> > Without having a source, I suspect a caveat wherein he will plug in to fully recharge the electric battery every X hours, which would be far less impressive.

FTA, FWIW: "McDowell 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."

Ah, thanks for that. I read the article fully, but apparently missed or forgot about that line in the first paragraph.

My intuition was that the Stirling engine would partially recharge the battery while it runs. If it can truly keep the battery fully charged, that is quite awesome. Time will tell. :)

Doing it with plugging in would be a bit pointless. You could do that with no fuel or engine.
This needs to be higher up. Likewise, a thermal cycle (Otto, Stirling etc.) doesn't get X% efficiency, an engine (running at a given hot/cold temperature with pumping losses etc) does.

Article says "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%." This isn't even wrong - the efficiency of both of these engines depends on a huge range of factors.