Hi
As with most things, the devil is in the detail and it is why you see Manufacture MPG and real world MPG and in the real world there are so many variables that they are only a guide.
I was thinking and adding to my post from last year regarding the MPG of my Niro and E10 petrol.
The listed MPG for my car is 64 miles (14.1MPL) but MY real world MPG was around 59 miles (12.97MPL) obtained by dividing the miles travelled by the amount of fuel used but with the very occasional 64 plus the odd 75 as displayed on the dash. Then came E10 and the cold weather and my MPG dropped to about 49 miles (10.77MPL).
After a number of months experimenting with my driving style and fuel, My findings have lead me the following:-
Driving style and the type of driving (e.g. Motorways, minor roads, average speeds 30/45/60/70) do have a major effect, fuel (e.g. E10 49MPG / 10.77MPL or E5 59MPG / 12.97MPL) and a BIG factor has been air temperature 10C or below wipes about 10MPG. I have found that if I accelerate at a steady speed and average 30MPH my dash shows that my average MPG reaches 75 Miles. These are my, none scientific findings, driving my M-HEV Niro 1.6 Petrol.
That is why Manufacture MPG should never be taken on face value especially when you hear stories of some who have taped over all the door/frame joints, tests carried out on a rolling road or circuits which are flat at a constant speed, none of which is real world.
I'm happy with 59MPG with the occasional 75 bonus.
Regards
Paul