deltafool117

How much is too lean or too rich. I have an SCT X3 and it reads 0.0 Lean, 2.0 lean, 4.0 lean etc etc or 2.0 Rich, 4.0 rich...etc etc

I have been bouncign from 2.0 Rich to 2.0 Lean just to be safe. I do not want to damage my engine. It is calibrated for 93 octane as well.

For fuel efficiency is 93 or 91 better... thanks.

JCON

higher octane is better for everything but your wallet. Higher octane allows the timing to be advanced thereby letting in more air to hopefully completely burn all of the fuel going in. Efficiency.

Going to lean or too rich is dangerous to the engine. Most engines run rich at higher rpm. I would wait for a tune to respond though since I've never played with the tunes, only loaded them.

DTMR

the thing that no one seems to have an answer to, that kinda bugs me is the whole standalone ecu thing. Apparently no matter how rich our lean we run the engines with the act we are still reading it through a narrowband reading and you're supposed to go to through a wideband sensor, and if you can't make your pcm accept the wideband reading you are only tuning so much but still there seems to be no standalone ecu for the s197 and no one seems to know if we can tune the stock computer to accept the wideband readings