Hi bignev There are alot out there who think an italian tune up is the way to go lol. Well why would you want to thrash your car to an inch if its life just to blow a small amount of crap out of the exhaust. well the problem is that is only a short term solution. The diesel we buy these days have a small and percentage of bio.which over time causes a wax build up in the system and also crystallisation around injection system. So thats why there are specialists cleaners to help remove these deposits. I use the same as you nev. I also use millers. As it gives back the cetane which is missing from fuel because of bio. So i also get a smooth running engine less diesel knock and a couple of mpg more. Which to be honest the book says 29mpg. Mine does 31.5. So not complaining with that