At 34mpg you're doing very well. My partner drives an 02 plate 1.8 focus and gets around 410 miles whereas the C-Max 1.8 struggles to achieve 360 miles. I've checked the specifications and the tanks are the same size (55 litres). Ford seem to have gone backwards rather than forwards. In my opinion, the engine has been married to the wrong gear box - in 4th gear at 50mph, the engine is reving beyond 3,000rpm, whereas the old focus is barely touching 2,500rpm. This forces you into 5th way too early and results in 4,000rpm at 80mph. If I'd know about the shocking economy, I would have opted for the 1.6 TDCi unit.