we use shell nitro in my Tiguan and the wifes mk6 GTD and the fuel usage is less but we both think the cars run smoother and seem slightly quicker when we put the food town and although its about 6 ppl dearer we find its worth it ...
It'll be interesting to see the result of a discussion between you and Monkeyhanger... he was less than complementary about Shell Nitro Diesel....
Not impressed with the Shell V-power Nitro diesel at all – as Corgi (and many other forum members )knows.
In summary, I decided to start my GTD on V-power, and for the first 3 tanks it was all I used. Never used the stuff before, save for a ½ tank fill-up on my Scirocco 170TDI.
It’s about 10% less calorific than regular diesel and was, as expected, giving me 10% fewer mpg and less power as a result. The power difference (low) was so pronounced that I was convinced there was something wrong with my GTD – it felt like it had about 160PS, as it was slower than my 170TDI Scirocco, but a smidge faster than my 140TDI Scirocco I had before that.
I had a look into tuning boxes because I was so disappointed with performance, had a tinker with them on a trial basis and decided that they weren’t for me while I have Bridgestone tyres (lack of grip in many situations was unreal with a bit extra power). I was getting a consistent 41/42mpg with the V-power in Sept, when the weather was considerably warmer, and as soon as I switched to regular diesel (Esso/Sainsburys), I got an immediate bump on my power and fuel economy which was then averaging 47mpg when not regenning, giving an overall average of 45mpg.
The car did seem to idle a little quieter on V-power and it regenned less frequently, but when it adds 20% to your fuelling costs per mile travelled (as a combination of higher price per litre and lower mpg), as well as knocking at least 10% off my power output, I decided it really wasn’t worth it. It seems a little cleaner (as you’d expect from the synthesised GTL portion of the blend) and more efficient in the combustion, given that it halved my regens. Considering its shorter average carbon chain, it’ll be less lubricative than regular diesel unless additives redress the balance and less potent.
Have a dabble in the regular stuff and see if your mpg changes vs Esso/BP/Shell fuelsave , you may be experiencing a bit of placebo blindness right now – “it costs more, so it must be better”.