I see more? as a change of the fuel mixture,
and not numbers of octane..
it is clear that a cold liquid has a different behavior..
but the octane is calculated on the basis of the point of detonation of the fuel..
and dir? pi? there are only two test benches all over the world and are found in the USA,
and it is a motor with a dimension to vary the compression and advance and other various tests that there is a way to test the behavior of the fuel..
and I think the evidence you should do is always to operating temperatures..
as an optimum fuel should be made of a warm engine, no? maybe you make corrections to cold temperature, but what we interrasse and 90?..