1. Until indicates the time of change of an activity or situation.
Pattern 1: verb + until + time
They waited until six o'clock.
The boys studied until midnight.
Pattern 2: verb + until + beginning of event
They lived here until their wedding; then they left.
She was busy until her graduation.
They didn't watch the game until halftime.
Myth about Airplanes
Higher octane is always better
Only if needed for antidetonation. Octane does not increase power. Higher octane is always more expensive, though.