My two yen on the subject:

One of the best tools a hybrid driver has, is the instantaneous fuel economy gauge.
I don't know about you, but prior to me driving a hybrid, I would do so many dumb things that kill FE, and I was not even aware of!

This gauge is one heck of an instructor, for any driver who is willing to use it, the nuances of improving FE.

So this is good news... any vehicle, regardless of the powerplant technology, can have one of these gauges for a minimal cost impact, and a substantial FE improvement.
Now the key here is "for any driver who is willing to use it". There is no substitute for the discipline required to achive high FE....... anything from driving style changes, to rational use of A/C, to air pressure verification, etc, etc, etc.