I believe this is true. in preparation for my EV i decided long before fuel hit £1.8 a litre of petrol that i would slow down. so eco mode is now always on(just dulls the throttle a bit ) try not to go above 60mph on the motorway and in the city i coast as much as possible and don’t worry anymore that some German car driver is going to pinch my safety gap by lane changing to save them selves 10 seconds queueing . and it works!!! I’ve increased my Honda Civic from a average 41mpg to 54mpg which might not sound like a lot but it saves just short of £60 a month.