50,000 miles in a 35iS

[Beeacon]

Putting premium fuel in a car with a standard ECU map is just pissing money down the drain. As said already, the cheapest fuel you can buy in the UK still exceeds the minimum.

Would that also apply to a remapped N52? or since a remap on the N52 doesn't bring about much bhp or torque increase, it's still ok with 95 Ron?

Not sure on the N52, but I know my N54 feels better on 99 RON with a stage 1+ map.

[R.E92]

Putting premium fuel in a car with a standard ECU map is just pissing money down the drain. As said already, the cheapest fuel you can buy in the UK still exceeds the minimum.

Would that also apply to a remapped N52? or since a remap on the N52 doesn't bring about much bhp or torque increase, it's still ok with 95 Ron?

Depends what was done in the map but unless they told you higher octane fuel is needed I wouldn't bother.

[enuff_zed]

Whilst it is fair to say that the car will run adequately on the 95 Ron, I wonder ifsunnydays comment may have more to do with the cleaning properties of certain fuels?
It seems to be generally accepted that Shell V-Power, for example, contains much better cleaning agents which are beneficial to the engine. This fuel is only available of course in much higher octane ratings.
Maybe, if there were a 95 RON fuel that was known to have the same cleaning properties as V-Power, more people would use that?

The engine management systems are perfectly capable of ensuring that the engine runs at it's optimum, as matched to the available octane rating. So we should be able to assume that the engine has not been under any undue duress. However, how clean that engine is could be another matter.
When people buy a car and ask what fuel it has been run on, are they concerned about the potential damage from poorer fuels, or are they more likely to be reassured that a car run exclusively on V-Power is potentially going to be much cleaner internally?