Use of higher octane fuel to pass smog inspection

I don't know why it would help. All higher octane means is that the fuel burns with more difficulty helping to prevent certain problems with engines designed for it or with carbon build up causing higher than normal compression.

messin with your octane , could make 'numbers' higher or lower a brand new air filter in my opinion would be money better spent

Between that and changing the oil right before going, I've had good luck.

Irv

Gaaaaaa!

Higher octane fuel is harder to ignite and _may_ send more unburnt crap out your tailpipe, especially if your plugs or valves are dirty. Your best bet, and something you should have done anyway is to follow the service intervals for your sparkplugs, change your air filter, run a can or two of Techron (or equal) through the system before taking it in (follow label directions), and getting it up to sustained highway speeds for at least an hour the day before the test.

A clean, well-maintained engine burning the proper grade of fuel will need no more than that to pass emissions-inspections. "Proper" is whatever the owner's manual states is acceptable, even minimally so. A poorly maintained engine may not pass whatever heroic gestures may be made prior to the test.

Peter Wieck Wyncote, PA