...yes, the "new" engine-management computers actually *WILL* advance the timing to "take advantage" of
higher octane (
less knock-prone) gasoline.
...that's *part* of the reason why some of the "newer" cars can often achieve better FE when using E85-fuel, which has 105 octane rating, due to ethanol's much higher octane rating (113) than 'straight' gasoline.
...so, the
real answer may lie in what year vehicle the guy was talking about--pre-electronics carburation, OBDI or todays' OBDII?