Toyota's Direct Injection Four-Stroke Superior version (D-S4) engine combines direct injection (which injects fuel into the combustion chamber) with port injection (which injects fuel into the intake ports). It controls the two types of injectors in accordance with driving conditions. Under heavy load, direct injection is employed. Under medium or high load, both types are used. In the drawing on the left, the engine uses both types of injectors (port injection is marked as "1" at the top). On the right, the engine uses direct injection only. (Source: Toyota)
Beth, I too am exited that these technologies are being explored and implemented. I am not surprised, because many of these innovations are not new, certainly start-stop technology is something that is not new and could have been implemented 20-30 years ago (has been on the Prius for 15 years). My hat is off to DN and Captain Hybrid for bringing some of the new technologies to light, we have heard too many excuses as to why we can't reach CAFE standards, and not enough examination of technology and innovation. These are only 19 ways (there are many more existing) that can be used to increase mpg ratings, not to mention ideas that have not even been thought of yet. Interesting that none of these ideas force cars to be smaller, and they don't even include hybrid technology. Coupled with hybrid/electric technology, the 54mpg standard should be met easily if we stop fighting about it and start engineering.
I agree, Beth. There are a lot of little technologies that eke out a few tenths of an MPG. The technology that will have the biggest impact, and will be most widespread, I think, is start-stop. Over the next ten years, we'll be seeing that on huge numbers of vehicles.
Wow, Chuck. I am duly impressed. I didn't realize there was such a wide swath of technology and innovations underway to address the 54.5 CAFE standard mandate. As you well noted, the focus tends to be on powertrain technology, yet there are many other places, many probably not considered, where auto OEMs can squeeze more mileage out of their designs. I particularly was impressed by the so-called "little things"--the improvements to making the wiring systems lighter and the flaps on the Chevy Cruze for aerodynamics. Very, very interesting stuff.
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