So I was wondering how some people were turning in huge fuel economy figures. Well, I took a look and most of them are some form of 'by display' meaning a Scanguage. I have one too but they aren't accurate for recording MPG's and I've never been able to keep mine calibrated well enough to use it for this.

So I pose the question that the GL's figures are inflated due to this approach exagerating the top end of the numbers.

Seems to me the only accurate method is distance travelled/fuel used or 'by hand'.