Short trip fuel economy

[vzsv8]

There is a massive retard in the spark ECT table at temperatures of 80 degrees or less and at light throttle openings. Is this just to reduce cat light off time, or an I missing something here. If this is the only use then it looks like there is a potential for a significant saving in short runs.
Any ideas? :?:

[GMPX]

You also need to look at table {B5956}, this is a multiplier for the ECT spark table. Notice it is not active (set to 0) between -20 and 80degC + between 0 and 1600 RPM, that means the ECT spark table has no effect between those ranges.
However, during cold starts etc then usually Cat Lightoff or Cold Engine noise reduction spark will be pulling the timing out.

Best way to find out is log the Spark PID's to see where all the timing is going. On a stock engine you don't normally notice much effect at the engine, but you add a decent cam, and pulling 15 degrees of timing out when cold can sure cause nasties!!.

Cheers,
Ross