How True

[TINO]

Sorry to ask this question but how true is the on board after a 400mile quick drive to fuel is saying to me at 60mph 40.1mpg. this can not be true.Also back at home yellow oil light every month about 800miles,tank it to scotland 600miles later no movement on the dip. 8)

 

[Taz]

if you are driving on motorway and being very careful, I would say 40 mpg is possible

 

[Half Colin]

The only way to be sure is to fill up, zero the trip and then note the mileage driven and fuel used next time you fill up. I've done this and found that the onboard computer is about 1-2 mpg on the ambitious side.