Direct injection means injecting the fuel directly into the cylinder instead of premixing it with air in separate intake ports. That allows for controlling combustion and emissions more precisely. But it demands more advanced engine management technologies.

On the face of it, GDI offers a potential 20% improvement in fuel economy and emissions compared with conventional gasoline engines.

The biggest problem of GDI is high cost relative to port fuel injection systems, GDI technology requires high pressure pump and high pressure injectors.
- - -

Despite what many green consumers might like to think, we won’t all be driving electric cars—or even hybrids—next year. Hybrids may be a much larger portion of the market by 2015—GM exec Bob Lutz says it may be 30 percent, certainly higher than the current 2.5 percent—but large numbers of cars between now and 2020 will still be fueled by plain old gasoline.

Within a couple of years, however, they will be much, much more efficient with that gas. And one way they’ll do it is with a new technology that’s about to spread like kudzu: smaller engines with gasoline direct injection, or “GDI.”

- - - -

At 19.5 mpg, 15,000 miles per year: 769 gallons gas
At 21.0 mpg, 15,000 miles per year: 714 gallons gas

55 gallons savings per year per vehicle is a nice gain, and at $4/gallon you're looking at a savings of $220 per year. Now that might not be enough to persuade customers for this van instead of another, but if they can get another gain next year you might be looking at a $400 per year differential, and that starts helping people to choose this van over the less efficient one, and saving a "barrel" of oil with every customer who switches.

It's not a big number, but at those low mpg vehicles every increase of a mpg or two has a tremendous impact on total gallons used per year.
Source(s):
http://tinyurl.com/d9vkza
http://tinyurl.com/cm8m5x
http://tinyurl.com/cbajhx

Asker's Rating:

Permalink | Report