Interesting results Ken.
I'm running on unwashed bio in my deuce and notice virtually no difference in MPG's, perhaps a drop from 9-10 to 8-9 during my most recent 2,000 mile trip, with more than half the distance covered on bio/veggie oil.
I have also noticed a slightly lower EGT and boost with biodiesel.
There are differences betwen the 6.2 and the multi, one of course is the combustion process. The hypercycle is a more efficient way to burn the fuel, but would effect all fuels similarily other than the higher oxygen content of the biodiesel, which combined with the hypercycle may help make up for the lower heating value (BTU's).
The 2-3% methanol content in my unwashed bio also helps increase the BTU value.
The heated fuel tank does have an effect on fuel delivery (see post on this elsewhere), but due to a malfunctioning valve, both diesel and bio were heated to about 120-135F during the trip.
I know I'm drifting off the subject of this tread, but the comparison is interesting never the less.