For anyone sceptical about the official MPG figures of diesels, apparently someone managed an amazing 97 MPG in a Gold TDI recently. And it wasn't a short trip either, a cross continent road trip of 995 miles. Good going!
Just because something is unbelievable, doesn't mean it didn't happen Charon. Maybe you should fly here and take part in the MPG Marathon, people getting close to 90 MPG over 2 days driving.
I think this high mileage third getting has to be on an overall downhill grade almost to the extreme. Does anyone have any information about that? I'm getting 61 miles to gallon on 23 mile drive into the city of Chicago but I think it's because it's mostly downhill. Driving an Audi A3 TDI. The best of gotten driving home is 47.
A 995 miles long hill? I don't think so! Haha! There are a lot of hills where I live too, great going down as you say, but unfortunately you have to go up them first which uses a lot!
I think the numbers are plausible. Just by driving a diesel quite slow can do wonders, which many times is a real challenge on good roads with +60MPH speed limits.
My best fuel up is around 54MPG going various speeds up to 65MPH but mostly around 45-55 and even some city driving included and even using AC some of the time. Automatic transmission, 177HP engine and 1,5tonnes of vehicle. I think those numbers can be improved.