I've read and understand all your replies to the 'my car doesn't achieve what the official figures say', but I have had a shock on my recent change of car. I have had a series of Volvo V70 D5's and been very impressed with the fuel economy; a 2002 manual achieved 46mpg, a 2005 geartronic 41 mpg. I have just switched to a 2008 manual, and with the same driving style only achieve 34 mpg.

This is right at the bottom of the 'real' figures on your website, with other drivers reporting 34.8-45.2 (I would be VERY happy with 45.2).

It has been suggested that this generation of Volvo is far less efficient because the Diesel Particulate Filter (DPF) strangles the exhaust. What is your view on this? Is the government insisting on a rule that increases fuel consumption?

It has also been suggested that I could have the DPF removed and engine remapped for economy by an after-market company, is this legal and does it work?