[PSIG]

The question is about Cold Advance: it is mentioned that this curve can be used to advance engine ignition timing while the engine is warming up. Expect that it would be used to compensate for WUE.

It is not compensation by the typical definition, but cooperative assistance when appropriate or set-up for it. Warmup does fine at the warm table timing used at that rpm, however, operation may be manipulated for certain effects. For example, if timing is manipulated at idle for torque-reserve or idle stabilization (common tuning techniques), Cold Advance can do the same to a greater degree specifically under cold start conditions. In-fact, in one form, Cold Advance can raise warmup rpm to a level that makes IAC operation minimal or unnecessary.

If readers are not familiar with terms such as torque-reserve, 'dashpot' function, or idle stabilization, this is not the post to cover all of that. The bigger point is that the engine is initially tuned with the minimum number of active features, in order to establish the best possible baseline operation. I feel this is important, as (example) active AFR correction can hide or even fight your VE tuning adjustments, rather than allow the engine to show how it likes your adjustment directly. I work hard at a really good baseline or 'base tune', that provides the info and basis for addition of features.

Once that baseline is achieved, we can then easily see what areas of operation are weak, or OK but could be further improved. Cold Advance is one of those tools in our toy box that might improve certain operational areas, but we need a baseline in order to know 1) if it is appropriate to use, and 2) when, how, and how much to use if so.