Hi all. I bought my 159 jtdm tourismo in Feb this year, 57k on the clock, and yes, I was a little disappointed it only did 42mpg at first but I wasn't surprised as my friend got similar from his Vectra with the same engine with similar use. I adapted driving style and achieved 44mpg. Then used Shell V power and achieved 46mpg with over 50 mpg on runs to Austria. Yes, driving for hours on end along autobahns will give the best but I didn't hang about with constant speeds ranging from 60mph (long lengths of road works) to 100mph (trying to make up time, and because I could). Also runs smoother with V power (I don't think I'm imagining it). Overall all I fill alternately with V-power and regular and achieve 44-45mpg on my normal runs. Helps to keep it clean I'm hoping. So, overall I'm satisfied with the economy; not the best in the class but then I didn't buy it on fuel economy alone. It's the best looking in the class by far but then you all knew that.