I haven't used one so can't answer your question but I have one of my own. What would you be hoping the treatment would achieve? Are you having problems?

 

I've been pondering buying some diesel additives. As i only ever buy supermarket diesel, i hear there's little additives to help clean the engine.

I wasn't planning on over-using it, was more of a once a month/2 months.

 

I use Archoil in mine 50ml per tank. Improves my mpg enough to pay for its self. Time will tell if it keeps things clean, I do notice it doesn't seem to regen as often so it must be doing something.

 

They do don't they, what's in V-power.

 

They do in Shell Vpower diesel & BP Ultimate diesel. It almost doubled the distance our old Zafira would do between DPF regens

 

Mazda use one called seafoam.

 

Morrisons don't sell V-power. I'm not driving out of my way for it either, Archoil costs around £1 per tank so it's also cheaper.

 

Premium fuels do contain them to begin with.

 

AR6900-D Max is the one i use, only one i could see that was aimed at Euro6 diesels.

http://archoil.eu/wp-content/uploads/2012/07/ARCHOIL-AR6900-D-MAX-Tech-Sheet.pdf

 

As Rob mentions, premium fuels are not as widely sold.

I'm not looking for mpg gains, i'm hoping the use of additional additives will help clean out the engine a bit more, and thus should prevent problems further down the road.

 

There is so little proof of they even work, but my car seems happy, increased mpg and less dpf regens to me seems it is working so I'm going to continue using it.

 

I occasionally chuck about 400ml of 2 stroke oil in my old PD130 A6 when I tank it up.
After about 100 miles it becomes noticeably quieter and picks up about 3-4mpg over the tank.
Bum-Dyno says it feels a bit more responsive too but I expect thats just the placebo effect.

I only put it in when I have some leftover from work. Usually buy a 500ml bottle of the cheapest green mineral stuff use about 100ml to mix up some 2 stroke for some kit then dump the rest in the car.

I keep meaning to buy a couple of litres and dose it over 5 tanks and see if there are any long term benefits but I've not been doing the miles nor do I have the motivation.

I do however recall the first MOT I had with it the emissions whilst a pass were close to the limits.
The 2nd MOT happened to be when it had some 2-stroke in as I was concerned it would fail, to my surprise it was about a third of the previous years test!
Same garage, same tester, same gear and had been serviced both times prior to MOT by myself.

With the above in mind I gave it the 2-stroke treatment prior to it's most recent MOT and the emissions were similar to the previous (different garage this time).

Read into it what you will, I'd not hesitate to put it in my A6 all the time if I could be bothered as it does seem to make a difference (at least on the trusty old PD130), however YMMV and I take no responsibility should your car self destruct the DPF clogs or you put too much red coloured 2-stroke in and get a tug from the Gestapo.

 

I'm lucky, my local Costco has just opened a petrol station so now I get Super-diesel for 108.9ppl

 

I think how well they work depends on the engine. In direct injection engines you get buildup on the back of the injectors themselves and you probably won't be able to wash all that away with fuel additives. It can be really bad in some diesels and symptoms usually start with miss-firing, running rough or poor efficiency.

In some recent petrol engines they have gone back to using port injection alongside direct injection to stop it happening (I know Subaru have with their boxer engines). That means the fuel can wash the back of the valves. Not sure about diesels though.

 

It's not the backs of the Injectors that's a problem, its carbon build up on the backs of the valves that causes reduced power and economy