Well, all I will say is this, Jesse. I'm on my 12th Nissan now, and my parents are also Nissan loyalists. At various points over the past 15 years, we've owned the same cars at the same time. Whenever this has happened, I've noticed differences between our cars that quite frankly boggle my mind. For example, at one point they owned a Pathfinder and my wife had the exact same model. When I drove their Pathfinder the first thing out of my mouth was 'What's wrong with your Pathfinder??' I mean, the thing was positively anemic. I actually popped the hood open to verify that it had the same engine it was so bad. Then I checked to see if they had something obstructing the gas pedal! That thing was awful to drive! Well, guess what? My wife and I have lead foots; my parents drive like grannies. My parents are the type of people I refer to as 'pylon-imitators' when they're on the road.
Now, take from that what you will. I don't know if it's the ECU 'learning' one's driving habits or what, but clearly something is adjusting to the way each vehicle is regularly driven. Also, I find your response to NizmoZ somewhat confusing. You wrote: "the car just has not learned what the engine needs at those conditions. once you put the engine in those conditions it learns what it needs and eventually feels better than before." Umm...doesn't your second sentence contradict the first? You begin by stating that the car just hasn't learned what the engine needs, then you state that once you put the engine in those conditions it learns what it needs.
I don't know, maybe I'm just not understanding what you wrote.
In any case, the point I'm trying to make here is that -- no disrespect to your resume intended -- but as far as I'm concerned, real life experience trumps all the certifications and courses in the world. I don't care if you have a Ph.D. from MIT and another one from Harvard. If your courses say xyz should function one way but real life empirical experience shows that it functions a different way, I'm going with the latter, not the former. In short, one should judge theory by empirical evidence/experience, not the other way around. That's common sense, right? Except I see people lose sight of this simple principle all the time. Far too often, I'll listen to some big shot academic with multiple degrees argue that someone's evidence must be wrong because it doesn't conform to his/her academic theory. That's bass ackwards, man. If the evidence doesn't support the theory, it's the theory that needs to be re-examined. I listen to these academic types attack the evidence without even considering that maybe, just maybe, their theories aren't 100% perfect, sometimes even suggesting that the evidence is fabricated.