In article ,
The Natural Philosopher wrote:
You have a car, and you have tow grades of fuel. You adjust it to run at
its best on one grade. It pinks like **** on the other, so you do your
best with the other fuel to get it at least to run without damage. You
achieve this. But now although its not as good as it was, on the high
grade fuel, its still better on that than on the low grade fuel.

You don't 'adjust' an engine to make the best use of a high octane fuel.
It needs/allows things like a higher compression ratio.

You design the engine for a target octane rating. Knock sensors then alter
the mapping if a lower octane rating fuel is used. There is no point using
a higher octane rating than the engine is designed for.

--
*(over a sketch of the titanic) "The boat sank - get over it

Dave Plowman London SW
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