Ambient temperature + tuning question

[rel3rd]

Is there a point where extreme (whether hot or cold) ambient temperatures dictate the ability to accurately tune or not?

In other words, if it's 100 degrees out, or in the 20's, how accurate is the VE and MAF tuning going to be once the ambient temps are back to normal, say 70* just for reference?

Just curious if there's a time when it's literally too cold, or too hot to get the desired long term results when tuning. Or if it is "best" to tune when ambient temperatures are "normal" (for your area) and let the extreme hot or cold weather do what it wants to do to your tuning?

[murphinator]

I think you will find many tuners have tunes for different seasons

[rel3rd]

I think you will find many tuners have tunes for different seasons

Really? I've never read/heard of that before. Not on anything other than Speed Density tunes, anyway.

I "assumed" that the PCM would self calibrate itself for extreme weather if the general tune is correct, or at least near-correct as it can be?

[S2H]

depending on the vehicle and OS you may have a temperature Bias table.
which is made to correct for varying IAT and ECT.
you can tune this table to get a more stable tune for changes in climate temperature
on my 2000 LS1 I found that my table needed to be a lot flatter than what GM put in there from the factory. others have found that their vehicles needed to be more agressive with a wider range

[EFI]

If you are using the MAF then it should not matter about fueling as it will register how much air is coming in and adjust fueling for that amount. Usually during the winter you can run more timing so that might be the only adjustment you have to make.

But even with an SD tune where it's all just a calculation and there is no actual air measurement, fueling doesn't get affected much. While doing my tune in the summer 80* weather, I've been driving in 30* weather now and the fueling is off by 2-3% at the most.