Comments for Mazda's Simple Engine Mod Burns 20% Less Gas at http://www.ecogeek.org , comment 1 to 4 out of 4 comments http://www.ecogeek.org Sun, 22 Nov 2009 09:42:16 +0100 FeedCreator 1.7.3 http://www.ecogeek.org/automobiles/715#comment-3019 I doubt it'll be less powerful as Hun suggests. The simple facts are that less power does not make a car more economical. A smaller displacement does, as it reduces the weight of the pistons and/or the distance the pistons get pushed back and forth. The simple fact is that if the car is now doing 20% more mpg at the same constant speed with the same shaped body, then it's become more economical at producing the same amount of power. Yes.. around town, the lighter weight will help with stop start driving, but not so much as to save 20% on fuel (otherwise a Lotus Elise would do about 60mpg, not 45mpg). - Neale Fri, 15 Jun 2007 22:48:54 +0100 http://www.ecogeek.org/automobiles/715#comment-3008 No mention of the power figures there, but I'm sure there's a power loss. Less power, more economical. Nothing surprising there, which explains why it needed to be accompanied by a weight reduction programme. - Hun Boon Fri, 15 Jun 2007 09:52:19 +0100 http://www.ecogeek.org/automobiles/715#comment-3000 As I have read a Miller-cycle engine leaves the intake valve open during part of the compression stroke, so that the engine is compressing against the pressure of the supercharger rather than the pressure of the cylinder walls. The effect is increased efficiency, at a level of about 15 percent. In the case of the Demio, additional effeciency in the [url=http://www.automotivemazparts.com/mazda-oxygen-sensor/]Mazda oxygen sensor[/url] at 5 percent make it overall in total 20 percent... As amazing as the car itself... - Sandman Thu, 14 Jun 2007 23:52:59 +0100 http://www.ecogeek.org/automobiles/715#comment-2995 Miller cycle is essentially the same as the Atkinson cycle used by Toyota's hybrids. Normally they are described as the same concept except that with a supercharger it's called Miller, without, Atkinson, so it's not clear how a non-supercharged Miller cycle is supposed to differ from Atkinson. Impressive gas mileage, but I'm sure the US version (if there was to be one) would have five times the power and one fifth the efficiency, unless there are some big changes in the automotive market here. - Michael Pereckas Thu, 14 Jun 2007 21:57:58 +0100