The lower engine RPM requires a wider throttle opening and the engine no longer is operating on the economical cruise mixture. It has been shown, however, that more of a lean mixture provides better economy than a rich mixture.

Consumers Union

I have no doubt that CU's mileage-widget and additive tests are more or less passably valid, because the science behind all of these mileage makers is nonexistent at best, fictional at worst. Therefore, even a marginally controlled, semi-methodical, grade-school-basic examination of them will reveal them all to be scams.

But, for products based on actual science (appliances, cars, engine oil, pencils and such), Consumers Union is definitely not the reliable, objective, expert source of unbiased information they claim to be. Much of the problem stems from their implicit claim to be so expert in every possible product or service that they can make up their own test protocols and parameters with unquestionable veracity. That is a ludicrous claim on its face, and the results they produce reflect it. Their assertion, for example, that 79?/qt Gree-Zee engine oil is every bit as good as $6/qt Mobil-1, is flat nonsense to anyone who has even a little bit of actual experience in such matters, or who's ever studied the results of oil tests based on applicable scientific principles rather than CU hype. Oh, sure, the test they concocted makes for good magazine reading (and therefore strong sales). New York taxicabs! ooOOooo! But a scientifically-rigourous test? A valid test for the conclusions asserted? Definitely not.

As a consumer, I can say this: After a suspiciously long string of bum steers from Consumer Reports?a couple of cars, a lawnmower, an answering machine, and five or six others?our family quit paying attention to CR's recommendations about fifteen years ago. Immediately, our consumer product and service experiences got very much better.

Not only that, but I have direct experience upon which to base this critique of CU's "science": I am an appointed member of the National Academy of Sciences Transportation Research Board Visibility Committee. We are the world's primary consortium and coordination committee for motoring visibility-related research. Two or three years ago, as a part of the NASTRB annual conference, we had a round table on headlamp performance and glare. A Consumers Union associate editor had requested and received permission to sit in, take notes and ask questions. Several of us spent a great deal of time explaining the issues and factors to this guy. We gave him a lot of material to take with him and all of us gave him our cards and welcomed him to contact us with any further questions.

The resultant CR article about headlamp seeing and glare was...bizarre. It was as though the guy had attended a wholly different meeting. The article was loaded with gross errors of fact and with unsupportable opinion presented as fact. The "rating system" CR has devised for headlamps has very little relation to the real world, and their suggestions for improved headlamp beams would be laughable if they weren't so pathetically out of touch with the optical and physiological realities involved. It's not just a question of "Dan Stern doesn't agree with Consumer Reports"; it's much more serious than that: Many of their assumptions and recommendations regarding headlamps are just plain nonsense fabricated out of the same whole cloth that allows CR to consider themselves expert in everything from red wine to oil filters to washing machines to insurance policies.

And I'm not the only one who's experienced this. I've got engineer friends in the filtration and lubrication and speaker industries, analytical expert friends in the insurance and financial industries, wine-expert friends, etc., and they all have the same experience when CU "rates" their industries' products or services: Fabricated "tests" having little or no basis in fact or sound science, with resultant garbage "ratings" and nonsensical recommendations.

It would be easier to stomach if CU didn't constantly crow about how objective they are because their magazine contains no ads. Aside from that being untrue (every issue is a cover-to-cover ad for CU's own products and services), tolerating their monthly BS is made more difficult when even carefully-written, thoroughly-documented objections to their ratings??if they are printed at all??are responded to with smug, smarmy assurances that CU knows best, and anyone who questions them must have unsavoury reasons for doing so.

As a consumer, I can say this: After a suspiciously long string of bum steers from Consumer Reports—a couple of cars, a lawnmower, an answering machine, and five or six others—our family quit paying attention to CR's recommendations .

I always give epinions.com a look before shopping for tools, appliances, even cars etc. They give unbiased ratings

I suspect the water is doing something else: filling the cylinder, which increases effective cylinder pressure. That's a huge advantage diesels have over us, no throttle means the cylinder is always full and the get their full static CR all the time. When cruising on part throttle, the cylinder is under high vacuum. Steam is a way to fill more of it without paying.

Glad you have had good success with epinions, but please keep in mind: There is no such a thing as "unbiased ratings".