Bruce Mallinson makes a number of points about efficiency (not just extra power) in his articles referenced at his business,
PITTSBURGH POWER. Look for a short series on an O/O named
A.J.
Also, Kevin Rutherford, in some articles online (he has a paying site).
Truckers Report may have a few tidbits. Use the above names and the topic to search over there. Both men bring up strong responses, so be thorough, IMO.
There are at least a half-dozen threads on this site in re Class 8 FE.
Do a search on
www.biglorryblog.com. to see what they're doing across the pond.