[Asterix]

Want to have my EGR valve cleaned with one of those additives, and is considering using some of the stuff in the tank on regular basis for better fuel economy.

Have any of you guys and girls used some off the stuff, and what are your experiences.  Does it do any good for economy, does the machine run smoother, less noise from the engine... 

[Phil №❶]

There's probably no harm is using additives provided they are suitable for diesel engines. I was a regular user of Redex in my petrol motors because these additives enter through the fuel system and help to lubricate the valve guides and upper cylinder. As petrol is a solvent, I figured it was a good idea. I don't recall any significant change in fuel consumption as the formula was only about 1 ml / litre from memory. IMHO I don't think it's warranted in a diesel, as diesel is already an oil. This is why diesels "generally" have a longer service life. 

There has been mention of EGR cleaning with a specific aerosol which will do the job in a couple of minutes, I'd try that instead. Naturally, I can't find the post for it now.