We have a 1.9 TDi Passatt, auto, deisel fuel consumption is excellent, we went from Stevenage to Aberdeen and back last year and spent about £100 in fuel including the trips we made up there. Our old car, Honda Shuttle 2.3 would us more than that just to get up there. I know it's not what you asked but it may give you another option.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.