How much?!

[dan_b]

Tesco99 is what you petrol boys should use, that stuff is proper fuel. I'm less convinced about the Ultimate/V-Power diesels to be honest and have stopped putting Millers diesel additive in too.

What I find totally annoying though is that these higher-octane fuels have been dressed up with these other so-called benefits/ additives and branding purely to enable them to charge a higher price. And yet I recall you can go on the Continent and high octane fuel is the same price as standard. That's what gets my goat.

My S2 ran like a dream on Tesco 99 - on a rolling road it was proven to get 15bhp more from Tesco 99 over 97 octane super unleaded (never put cooking fuel 95 octane in!). I remapped my A4 V6 on Tesco99 and got 6 degrees more advance with it on over the standard 97octane map.

The other annoyance - super unleaded used to be 98 octane - the same as old fashioned 4Star. Why did it unilaterally get cut back to 97 in the UK?

I can just about remember you used to be able get 5 Star petrol - 102 Octane I think?

 

[mjhamilton]

this does depend a lot on the car.. my Civic Type-R is mapped to 95 RON fuel.. if I put 97/99 in the tank I am just pouring my money down the drain.. I do not notice any difference.. in most cases people that say they do are just using their butt dynos to justify the extra cost...

... now if I were to remap the car to work with 97/99 then of course there would be a big power difference on the vehicle, but then I would be trapped at this fuel at that price

That was the Honda EP3.... but this is not true for all vehicles.. most VAG cars has a variably mapped knock sensor and ECU that adjusts dynamically and thus if you put various types on RON in the tank it will after a few miles adapt and you will feel the benefits of the fuel you are using..

Just thought I would add my two cents