BMW 525D Touring (not and estate Rob
Motorway journey at 65mph averaging in the region of 50-55mpg so by my calculations around 750 to a tank (70litres) does about 40-45mpg driving round town. If I stick to 56mph have got a computer reading of 67mpg which I think is a bit optomistic.
Can fit me + 3 with 4 softcases, 1 air cylinder and associated bean bags.
60L tank is giving just over 500 miles at 70-75 on motorway, which it will do loaded up...
Also you are a very naughty boy doing that upper speed