I started investigating the Mazda 6’s trip computer while on a motorway journey the other day.

It includes a graphic showing the i-Eloop system, which in very simple terms is the battery that runs the car when the stop/start system is, er, stopped.

What I noticed is that the car continually charges the battery when cruise control is used, but that without cruise at the same speed it does not charge the battery.

As the i-Eloop charge system puts extra load on the engine, this may go some way to explaining why I’ve not been achieving impressively high fuel figures on the motorway when Mazda claims a 74.3mpg extra-urban official figure. Indeed,

I seem to be able to get better economy stats driving in suburban areas or on country roads than I do on motorway journeys.

Unfortunately, I don’t think I could suffer trying to hold a religious 70mph on the motorway without using cruise control, so I may just have to live with a less than perfect low-50s mpg figure for longer drives.