Ethanol in petrol

[ROGER COOPER]

Interesting information on fuel. UAE57N runs on whatever Sainsburys have in their higher octane pumps and seems to perform satisfactorily. If I drop to the 95 octane stuff it will pink a little so I use that only when there is nothing else available when out and about. Being a slightly cynical one time employee of a major petroleum company I am not sure I would notice any marked difference if I switched to named brands.

[ROGER COOPER]

Considering that all this stuff probably comes out of the same bulk storage tanks in Rotterdam, I wonder just how much difference there really is - do the major supermarkets actually put in different additives to make their brand unique?

Also, although pumps are supposed to be clearly labelled about ethanol - are they? The staff on the forecourts seem to have no knowledge and even less interest so finding out the truth is made virtually impossible!

[Peter Cresswell]

Roger
Some interesting points you raise here!
As I understand it, every retailer does indeed start with the the same petrol (that is the minimum standard it can be), but the big brand retailers (Shell, BP Esso, Texaco, etc) then put into the mix additional additives which help the engine run smoother and be a little more economical. I suspect Tesco just put in an octane booster to push their super unleaded up a notch to 99RON.
I know my MG6 returns better economy on long runs I regular make using ordinary Shell over Morrisons, and if I use Shell V-Power unleaded it picks up quicker and smoother from low revs and does even better mpg. Figures typically are 32mpg on Morrisons, 35mpg on ordinary Shell and 37mpg on Shell V-Power. Admittedly the figures come from the onboard computer, but represent around a 10% better economy between supermarket and Shell ordinary, and around 13% better on Shell V-Power. The difference between the Shell fuels is negated by the cost, but represents a real saving between Morrisons and Shell as they price match locally. I also understand that this is a typical finding for a turbo car.
I do run my MGB (and previous 1293cc Mini Cooper) on Shell V-Power, and currently use Castrol Valvemaster Plus as the head hasn't been converted (a winter project), and if I have to put in regular fuel I add a bit more Valvemaster to push the octane number up a bit. I do know of people whose MGBs run terribly on Tesco, but as soon as they fill up with Shell V-Power they run very well.
Also remember the recommended octane rating for the B was minimum 98 octane but I'm not sure how that varies between leaded (the recommended fuel) and unleaded. Might be belt and braces on my part, but then all the differences might just be smoke and mirrors - so long as it's not seen IN the mirror.