My good friend Keith was kind enough to give me an overview of his real world mpg experience driving a Mitsubishi Outlander. He even took a few pictures of the control panel to illustrate things. (Many thanks).
“Usual caveats about how your mileage may vary but on my daily commute (36 miles each way) on fast country roads with the odd 30 mph through villages and a brief junction on the M11, I get low to mid 30 mpg on the return run when the battery is discharged. Though actually it never completely discharges, what happens is that the black box will charge the battery from engine or regenerative breaking and then use that when it feels like it. Hence the 61% EV on one of the photo’s below.
On longer runs with lots of motorway and cruise control I get mid to high 30’s although it falls off a cliff if you go constantly over about 75.”
Interestingly, the graphs seem to indicate a much higher energy efficiency for short journeys, which is what you’d expect with a plug-in hybrid.