Jeff Bayliss

Hi All,  I use supermarket diesel in my Mondeo 2ltr estate ( sorry hopefully a Jag XF Sportbrake next year! ) and use Cataclean Diesel additive every 4 months. MPG has improved now to 56/ 58 mpg and never had an issue with a failed DPF regeneration. Its quite funny though when it regens, goes a bit sluggish until you put your foot down in 3rd a big cloud of grey soot comes out the exhaust! It then clears and is good again for around another 500 miles or so. Its a 2009 Zetec model by the way with 168k miles on it. 

Also low ambient air temperature can stop it working? I know this happens with Mondeo`s. Conditions have to be "right" for the stop start to work. Might be worth looking in owners manual - basic I know but worth a look.