This appeared in latest Auto Express:

"A clean engine is a more efficient engine which is why BP Ultimate can offer unleaded users up to 28 more miles per tank and diesel users as much as an extra 22 miles per tank. Over an average year that adds up to a lot of extra motoring...
Due to its superior engine cleaning power plus higher octane level, BP Ultimate unleaded drivers can experience power gains of up to 7%, and the higher cetane rating of BP Ultimate diesel alongside its amazing engine cleaning ability can also give power gains of up to an impressive 8%.
That more powerful punch in your tank allows acceleration to increase by as much as 5% for unleaded and up to 8 % for diesel. For BP Ultimate unleaded that's like upgrading your 2.0-litre model to a 2.3-litre".
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I used to know a chap who worked at the Oil refinery at Fawley. He was quite adamant that all the tankers (Esso, Texaco etc) left the refinery with exactly the same fuel mixture. Anyone know if there is a difference between fuel brands?

supermarket fuel used to play havoc with my old 2.8i capri.

Its the detergents and other additives that are added to 'branded' petrol rather than supermarket stuff.

I know quite a few people who use Shell V-Power (was Optimax) and have used it myself - it stopped my E230 pinking while I sorted out what was causing it.

I tend to use ordinary but not supermarket fuel and fill up with 'super' fuel every 3 or 4 tankfulls.

Every power gain mentioned in that article was prefixed with the words "up to" or "as much as". The different "high-performance" fuels (Shell Optimax, BP Ultimate) do have a higher cetane rating but we all know that the ECU has to recognise this and adjust its map accordingly or there is no performance advantage and no fuel saving.
I used to fill my 147 up at Morrisons...now I fill up at Shell. It's made no difference to the performance and the mpg is still the same. The only reason I changed was because the Shell garage is on my way to work.

quote:

Originally posted by Alfisti147:
Every power gain mentioned in that article was prefixed with the words "up to" or "as much as". The different "high-performance" fuels (Shell Optimax, BP Ultimate) do have a higher cetane rating but we all know that the ECU has to recognise this and adjust its map accordingly or there is no performance advantage and no fuel saving.
I used to fill my 147 up at Morrisons...now I fill up at Shell. It's made no difference to the performance and the mpg is still the same. The only reason I changed was because the Shell garage is on my way to work.

Not entirely true there Alfisti but you are along the right lines. Yes in regard to purely Octane rating, you require a knock sensor which then adjusts the fuel/air mixture via the ECU giving you the outright power gains found with some of the super unleaded fuels.

However, with Optimax, BP Ultimate and even more so with V-Power, they include detergents, additives and extras which aid the engines lubrication and running in other ways, independent of the mixture alterations. V-Power includes a special additive called FMT, used by the 2006 Ferrari F1 team, which lubricates the valves and pistons, meaning they operate easier, meaning the engine revs more easily there making it faster.

It's not as simple as just saying "Oh, Esso Supreme is 97 RON and BP Ultimate is 98, therefore BP Ultimate must be better"

Personal experience is that Shell fuels, even the 95 ron stuff, is just far superior in my cars than any other. V-power makes my car fly. I ran it on V-power for 3 whole tank fulls, then had to fill up with Esso 95.

The car felt so slow and the engine was quite coarse. Back on to V-power and it started to pick up better straight away, although it wasn't perfect as it was a contaminated mix.

Im my experience BP Ultimate is about as effective as dishwater.

The fuel does come out of the same tanks but as stated earlier, additives and other processes are got on with.
Interesting fuel test.

It will also depend if your car can run higher octane with the benefits other wise its a waste of money.

I haven't got a clue about all this. But how much difference would it make to the normal family saloon?

Performance wise, not an amazing amount but it will be better for your engine and in normal driving you will see the small extra back in increased econonomy.

I'm in the middle of a rather unscientific test of Supermarket fuel (Tescos in this case) and Shell at the moment. I found out that Tescos are selling Biodiesel and so deceided to see if it was any better.

The plan is to fill up when the fuel warning light comes on - three times with Tesco and then do the same with the Shell (which is my regular fuel) - hopefully that should give a reasonable comparison as the journeys i will be undertaking are all very similar.

So far I'm on my second tank of Tescos (due to fill up tomorrow) and it ain't looking too good - fuel consumption is down at 54mpg as against Shell's 57mpg and it doesn't feel as responsive - but I'll only know when I put Shell back in again.

BTW the Shell is the standard stuff, not the expensive stuff they sell.

I make regular trips up and down the A1 at off peak times and for the last few months have been playing the economy game. If I stick at 60mph with the lorries I can manage about 340 miles to the tank before the fuel warning light comes on. I continued to do this for 5 or 6 tank fulls and then had an experiment to see what the effect of thrashing my little car would do to the fuel economy. I managed 260 miles to the tank, which was better than I expected considering these were all shorter journeys and that I had my foot to the floor a lot of the time.

I slipped back into sensible driving again and regained my economy, however last week I pulled up at the wrong pump at BP so I filled up with their "BP Ultimate" instead of the normal petrol I usually have. I can feel a difference in the acceleration if I put my foot down, but I am not convinced on the economy side of things. I've covered almost 210 miles on approximately 3/4 of a tank so I would imagine I'll get to about 280 miles before the warning light comes on. I don't think its worth paying the extra for the fuel on grounds of economy alone.