Hi folks,

I recently bought a '95 Mystique GS. My other cars are '78 Fords, where the most complex engine component is the Duraspark electronic ignition, so the Zetec's somewhat foreign at this point. Question for y'all:

How is ignition timing set by the engine computer? The manual says to use 87 octane gas; will the timing be automatically advanced if I put in 93 octane? Does the computer adjust base timing, advance timing, or both?

Thanks for your input!

Po

Po 1995 Mercury Mystique GS: Zetec 2.0L I-4, CD4E 1978 Ford Thunderbird Town Landau: 351M (5.8L V-8), FMX Coming in 2007 -- 1986 Jaguar XJ12 Sovereign: 5.3L High-Efficiency V-12, GM transmission