AutoblogGreen

"It's a system, though, that you can't see yet."

Uh-uh, sure. That just means that it doesn't exist. And might never exist.

However, it's certainly theoretically possible (barely), since the best current technology for gasoline ICE runs a little shy of 40% efficiency. You would need to double the efficiency (plus a little more) and figure out ways to make the rest of the car take less energy to move, but it's at least theoretically possible. We already have diesel passenger cars available at real-world dealers that get close to 50 real-world mpg.

Waste heat is going to be a tough one, since the ICE is basically a heat engine. Double-talk about reducing waste heat is probably just calculated to bamboozle people who aren't well-versed in the laws of thermodynamics.

I'm not going to hold my breath waiting on vaporware. The folks at Transonic can put up or shut up. If they have something patentable, then they don't need any NDA bullshit. And the US automakers have such an advanced case of NIH that nobody needs to worry about their ideas getting stolen anyway.

Next time I need a new car, I will look around and buy the most fuel-efficient one that I can actually buy that still fills my transportation needs, just like I have always done. I kinda hope that the next time, it will be an EV, but I'm not holding my breath for that one, either.

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I'm more certain that it exists but the *cost* is likely to be so high that it would render any fuel savings pointless.

Economics is right at the center of the energy problem.

The question is not whether energy can be saved / generated with a new technology but whether it can be done ECONOMICALLY.

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I know there's at least one Automotive X-Prize participant who claims that a revolutionary engine upgrade provides 100 miles per gallon, and will use it in the race.

So such a claim is not new. What would be new is an actual working vehicle.

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"compression rations" -> "compression ratios" :-)

The only way to drastically improve gasoline engine fuel economy using only an improved injector is spray-guided stratified direct injection. BMW and MB both already have such systems in production. Stratification means you run the engine globally lean, which sharply reduces your pumping losses in part load. It also means you have to use an expensive NOx aftertreatment system. And as with all GDI systems, the cooling effect of vaporizing the fuel in the cylinder means you can raise the compression ratio by approx. 1 point (to 11.5-12.5 in a naturally aspirated engine) without risking dangerous engine knock when operating near rated power.

The key to success is ensuring adequate mixture preparation prior to ignition. Any fuel droplets that have not yet vaporized as well as any locally very rich zones in the gas mixture will cause particulate matter. Indeed, early attempts at stratified GDI were no better than diesels in this regard. Only extremely tight - read: expensive - manufacturing tolerances on the relative position and angle of injector and spark plug solved the problem.

Now to this proposal: injecting liquid gasoline featuring "ultra-high" geometric compression ratios will cause it to spontaneously ignite before a proper air fuel mixture can form. Cp. conventional compression ignition.

However, unlike the long-chained molecules that make up the bulk of diesel fuel, the lighter compounds in gasoline do not exhibit what is called a negative temperature coefficient (NTC). This is what causes the ignition delay characteristic of diesel fuel, without which diesel engines could not operate properly. Further reductions in PM formation require extremely high injection pressures to assist in mixture formation in the piston bowl; the state of the art is 2000 bar.

Without NTC, gasoline fuel has no inherent ignition delay so mixture formation would depend on injection pressure alone. Forced into compression ignition, the flame fronts will propagate very quickly. If the mixture preparation is not yet complete, PM, HC and CO emissions will all be high and fuel economy low.

If mixture preparation is complete - a very difficult trick in these circumstances - combustion will be near-isochoric and therefore indeed very efficient. It will also be very loud and place very high stresses on the engine casing, cylinder head and crank train. For all intents and purposes, the combustion process would almost be a case of controlled engine knock. That's fine for F1 engines with compression ratios of 16:1 that are running at 19,000 RPM and only need to last for two races. For a conventional LDV gasoline engines, severe knock must be avoided.

Note that HCCI combustion is also based on controlled auto-ignition. However, it usually relies on high rates of retained (hot) EGR to control both ignition timing and heat release rate. MB's DiesOtto concept does include a fancy variable compression ratio (VCR) mechanism for HCCI control, but so far it represents an exception in this field. And while GDI is generally recognized to greatly increase the portion of the engine map in which HCCI is feasible, everyone injects early enough to achieve a near-homogenous mixture throughout the combustion chamber.

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gastankmizer.myffi.biz is web-site for a company with proclamations of conservation of fuel, heat, pollution and engine life expectancy available now in the USA (EPA registered) and 190 other countries. Copies of research data, both US and foreign, and/or brochures available upon request.

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Rockefeller seed capital isn't known for chasing rainbows. http://investing.businessweek.com/research/stocks/private/snapshot.asp?privcapId=23721

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