I've just started on my 3rd tank of this Shell V-Power Nitro+ Unleaded - Shell United Kingdom It's about 3p a litre dearer than the bog standard stuff and I have to say I'm impressed. Engine starting has improved (not that it was bad before) but it just feels slicker. Engine noise appears to be that bit quieter and feels a bit quicker on the take up. All a bit subjective I hear you say but the real bonus which I can see, is the increase in MPG; currently achieving around 3 MPG more (average that is). I haven't done the maths yet as to any economic gain but I'll be quite happy to put this motion lotion in the tank for the foreseeable future.