I would have thought that the ability of the B58 to get such good MPG is enhanced by the 8 speed auto allowing ultra low revs at motorway speeds.
My N52 powered manual 130i will average 35MPG when cruising at GPS 70mph on long motorway journeys. I think revs are up around 2,750 at that speed.
Yeah that definitely helps. I know on my v6 diesel with the 9 speed auto box that at 70mph with ACC on the engine is barely ticking over, i think its 1500 rpm at that speed.
Old 5 speed or even 6 speed gearboxes count have kept the car at 70mph and revs under 1500.


Service packs etc are down to each individual country, so it'll be totally different there. My comments were based on the UK situation 