Okay, I haven't yet picked up my car so I can't try anything for myself, but:
I fairly regularly do a run from Leeds to northern Scotland, 500 miles total. Leeds to Glasgow, 250 miles, is all motorway so ~80 mph, Glasgow to Inverness is single / dual but average speed cameras keep me to max 60 for ~130 miles, the rest is then single track with passing places so ~60.
I used to do this in a Volvo and as far as Inverness it's in cruise all the way.
In the Beemer I was thinking to put in Eco Poo and cruise for max efficiency but I've been seeing on here that cruise doesn't use the freewheel mode of Eco.
So what's my best bet. Eco poo and cruise, Comfort and cruise or Eco and no cruise?
I'm not that fussed about mpg but on that journey up the M6 and M74 I'm limited by camera vans on bridges anyway so why not try for the best I can?
Once passed Inverness the stick will be going left
