Not exactly anything new or exciting; based on the (high) average fuel consumption (mileage), the main factor here was an enormous fuel tank.
There are true candidates for "hyper miling" that would have been interesting to see, including the European version (with current low emission features - undefeated 😜) of the VW Passat 1.6 TDI; such a car was recently driven over 1.300 miles on a single tank from the UK to Africa (!) And it was all stock, no extra fuel tanks, no special mods It would have been interesting to see that kind of highly efficient engine in a plug-in hybrid with smart engine management and at least 30-40 miles of range on all-electric. And, while an all-electric vehicle is better for the environment (and enough for my use case), this would help people get over their range anxiety.