E10 petrol degradation over time.

[Harrier Man]

I was talking to a garage mechanic this evening who was an advocate of E5, okay so far, then he went on to say that he never used Esso fuel because as well as the addition of methanol, suppliers mix bio fuel with oil fuel and Esso use a higher proportion of bio than other suppliers. He went on to say that VW say that bio fuel should not be used, using this as evidence that fuel with a higher bio content was less good that fuels with a low bio content. Other comments he made about other matters were total rubbish so I'm left wondering what the truth of the matter is. Any experts out there that can enlighten me?

[WhiteHart]

Still cannot drive my 450+ to it's full potential as I only going to and from work so have not emptied tank of E10. Went away for a long drive on the first weekend after I got it and came back and before I read this post I full it up.I keep on driving in charging mode just to burn the fuel. Hopefuly be driving it properly by Monday.

[Warthog001]

If you need to fill with E5/high RON fuel I suggest you use a high volume filling station as the fuel can degrade in the station tanks if it's left unused.

I have had high performance cars for the last 20 years and used to use additives until a few years ago I spoke to someone who was an expert in fuels.  Essentially, he told me that there are only 2 types of petrol (E5 & E10,  or standard & premium) when a tanker fills at fuel depot a container of additives is added to the raw petrol to protect the engine and increase performance (recipes vary).  Supermarket fuels add little or none to keep the cost low.  The combination of high octane, low ethenol and protection additives should deliver the best performance.  My Jaguar XFR hated standard fuel and my current BMW is more tollerant but still works better using premium. Shell V-Power seems to deliver the best results for me but I have used other brands of premium fuel and not noticed much difference.   

I have just ordered an NX 450h+ F Sport as I'm not ready to go full EV.