Does anybody is Millers Diesel additive? What difference does it make in terms of power and or economy? I've also read that using Jaso 2stroke oil is worth using - so which is best? I'd be using it in 2013 RRS SDV6 and Defender 90 2.4 Puma  Cheers Laurence.

Likly to make things last a little longer rather than instant noticeable improvement.

Dint bother on defender.

I use it in my 2012 SDV6. Feels like it drives marginally better and pulls a little stronger. Can't comment on fuel economy savings as I haven't measured them. Agree with Andy's comment this should be seen as more of a long term preventative measure: having acquired mine on 40k miles and now at 100k no injector or fuel system egr dpf issues at all so far. Potentially bp ultra etc might have the same effect but with millers you control the dosage at 1ml per litre though you can add more, say 2ml litre and there is to me a small but noticeable performance and driveability improvement.

As to two stroke... I wouldn't personally feel comfortable. This is not a two stroke engine and google search returns mixed views it is fair to say.

Discovery owners (of similar engine) love the 2 stroke. Again preventative measure towards the injectors and high pressure fuel pump

I use their injector cleaner additive in my TDi300 Defender over a couple of tanks full every couple of years - as I only do about 1500 miles a year and driving conditions vary hugely I cannot say whether it improves anything, but the emissions are always low come MOT time and the tailpipe has only a tiny amount of carbon on it. When I had the SDv6 RRS the emissions of my 22 year 90’s ancient turbo diesel with no emissions controlling equipment were always lower than than the RRS’s with all its tech........... 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW