Originally Posted By: pacem
I fueled up with 89 Octane, thinking the tuner would come with the 89 Octane tune.
No such luck, it goes from 87-91-93. No 89 option. All gas in my area, almost all does not offer 91. I think I will fill up with 93 mixed in with 89, should average out to 91.
Supposedly going to straight 93 is also OK. what is not OK is tuning for 93 and then filling up with a lower octane.
I added some Octane booster to boost my 89 octane into 90 or 91, not sure how that will end. It's just one tank of gas. thus far no pinging.
Minor improvements all around, smoother and more responsive shifts. It's the cheapest way to get some benefits out of it.
When in doubt about the quality of the gasoline, whether or not the octane levels are sufficient, etc. you can use the tuner to generate datalogs while driving that can help answer those questions, verify assumptions, etc.
I am not familiar with the specific PIDs for the GM PCM, but anything related to KR (STKR and LTKR), throttle position, spark advance, and the like should be the minimum set of PIDs to record. Be sure to record the datalogs while performing all manner of driving, e.g. 0-60mph runs, stop-and-go traffic, hiway cruising, etc. If KR is observed, look for patterns to the spikes such as only at WOT (and in what RPM ranges) or immediately after long bouts of stop and go.
It will take some work to gather all the data you need, but eventually you should have a pretty complete picture of how the engine is handling the loaded tune and the provided gasoline (as in, "handling everything well", or "too much KR, something's not right, need to step down to cooler tune...").
