REPORT (1992): Auto FE: How Far Can We go? (a few notes)
 

I found this interesting, and I thought I'd share and see what others find believable.

From "Automotive Fuel Economy: How Far Can We Go?" (National Academies Press, 1992) by "Committee Staff on Fuel Economy of Automobiles," Appendix B, p.202:

1 - claims that 5-6% increase in compression (9.0:1 to 9.5:1) would yield 1.3 to 2.0% increase in FE.

2 - On p.205-6 under "variable valve timing" Honda's VTEC-e in the VX is specifically cited as producing 15% more torque at 2000 rpms than the DX. The report claims Honda asserts that VTEC-e along with lean burn produces 10-15% greater FE but even without lean burn the variable timing still produces 7-8% better FE.

3 - On p. 212 the authors of the report (not Honda) claim that aerodynamic differences between the VX and DX account for 0.7% of the FE improvements in the VX. [I wonder what the differences were?]

4 - On page 212 the report claims that a 10% decrease in drag will produce a 2.3 or 2.4% increase in MPG.

5 - On p. 212, a 10% weight reduction yields a 5% increase in FE.

Link or it didn't happen!

No can do. These notes are from an eBook available through my university library. Restricted access. A complete citation and page numbers are enough for you to fact check if you want to be that skeptical. Here is a copy you can buy online: Automotive Fuel Economy : How Far Can We Go? by Committee Staff on Fuel Economy of Automobiles and L (editor): National Academy Press, Washington, DC, U.S.A. 9780309045308 Soft Cover, - Longaeva Books

And here is a google books link to the executive summary, describing how the report came to be: Automotive fuel economy: how far should we go? - National Research Council (U.S.). Committee on Fuel Economy of Automobiles and Light Trucks - Google Books Looks like you might be able to read parts of Appendix B there.

...what do you think about the content? Is there some basis for your skepticism?

We can go a lot further, definitely !

Jet's take Piwoslaw's car and its 1.6L HDi PSA diesel: 43 mpg - 5.5 L/100km in his 2005 Peugeot 307SW.

The same engine in my 300lbs heavier 2005 Volvo V50: 47mpg - 5.0 L/100km.
In the 2009 (?) V50 Drive : 4.5 L/100km - 53 mpg
In the 2010/11 V50 Drive Start/Stop : 3.9 L/100km - 60 mpg.

In mpg, that's a 39.5% increase, or in L/100km a 29% decrease.
For the same engine in very similar cars, over only 5 years.