Quote:
Originally Posted by 2forme
I was under the impression that the MPG calculation was based off the injector duty and not the airflow.... The injector duty is calculated from the airflow reading and load (amongst a few other things). So it would be calculated AFTER the airflow was already analyzed and not during...
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If the airflow reading is skewed in particular conditions, that propagates through a bunch of other calculations. These calculations include fuel trims and engine load used for enrichment scheduling. It also throws off any correction factor used to more closely align the MPG calculation with laboratory tests using fuel flow meters.
Changing anything related to the MAF or the fuel system actually skews a ton of stuff. It's not something to take lightly. The ECU is smart enough that you as a driver usually won't notice it but on a lot of platforms an intake mod is a huge deal. A lot of people remember putting an ebay cold air intake on some 90s Civic without a MAF sensor. So they don't realize how an intake change has so many implications on a modern vehicle.