I've now had my new Ford Galaxy (2.0l TDi Manual) for just over 5 months and have racked up about 5,500 miles so far. In that time the cost of diesel has got from around 98.9 pence per litre to 108.9 pence per litre and petrol from 96.9 pence to 104.9 pence.
For my last tank of fuel I decided to drive a little more carefully and see just what I could get out of it, my best to date had been 570 miles with 3.5 litres left. An average of 39 miles per gallon which is not too shabby considering the size and weight of the car. My old Galaxy (2.3l petrol automatic) would average 23 mpg or 25 on a good run.
I tried a few things, I only put on the air con when needed for demisting, I accelerated gently, gave myself more room to other cars to allow me to maintain speed and approach junctions more carefully, again to try and maintain momentum.
The other thing I did was to use the cruise control a lot to maintain a steady speed and not allow other people to hurry me or try and drive faster up hills.
The end result, 631 miles on one tank with 5.5 litres left. 44 mpg!! and nearly 3 weeks between refills. In fuel alone, the new car costs 11.3p per mile. The old one at todays rates would cost 20.71p per mile. To put it another way, those 5500 miles on the old car would have cost £1158.85 in fuel, instead I've paid just £621.50, a £537.35 saving. I'm happy with that!