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Okay, I think I found this curious bit of the spark table around 2000rpm where the factory seems to have mysteriously pulled several degrees of ignition timing, and I discovered that Aston Martin was too lazy to calibrate IAT and EGR spark compensation, just zeroing the tables out.
If this is what I think it is, I think I am seeing 20 degrees at 0.3 load, and 24 degrees at 0.4 load, which ... makes zero sense to me. You cannot limp the car home at 0.3 load, it would barely move.
It's possible I am over 10 degrees off MBT ignition timing right now, which could easily cost 10% efficiency, whereas before I was only off by maybe 4-5 degrees. I think there is something going on where the car is using a super conservative knock adjustment table that is pulling low load timing where it really doesn't need to, and the 91 octane California fuel is making it lose part load fuel economy. Moving the intake cam increase MBT spark advance even more, and now I'm off by enough to make it lose significant mpg.
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