ORIGINAL: Blackflag
But you do have a choice. The OEM's won't release their engine/dyno data. But you can read books on engines, and you can read the technical papers published by universities and research organizations, like the D.O.E. You can even read the little bit of stuff that the big 3 engineers do decide to publish. The engineers at the big 3 read all that stuff ... to see what else is going on in the world. They also look at what's being done in Europe/Japan, which you poo-poo. Believe me, they look at those engines in depth, buy them, run them, tear them down. But you'd have to want to be a hard core engine guy to go through all that stuff, it's a lot of work. Have a sweet weekend, baby!
I have read enough information that lead me to my view on this and have been able to actively defend my perspective without using multiple other examples I have that could weaken any of your other points that you have made thus far. Obviously those books and universities have trouble educating people on the simple fact that certain 2 valve OHV engines and 2 valve OHC engines are from the same family as certain 4 valve OHC engines and that in the process that the fuel economy has dropped during the transfer. Not too suprising since most of our country doesn't have any clue about our own national history (or anyone else's for that matter), I wouldn't be surprised if universities are incapable to see that your theory is incorrect no matter how much evidence there is to prove that 4 valves are less fuel efficient. There are a few other theories out there that supposively improve fuel efficiency that simply make it worse as well.
Your missing the point of why the Japanese and Europeans use such engines. It's primarily for marketing purposes. Generally a 4 valve OHC is more refined and quite than a 2 valve OHV engine, plus its the bragging rights purposes (I can get 268hp out of this engine while there engine of the same size only produces 224hp). Performance is the factor that drives this, not fuel economy.
Hmmm. They have all this information and GM and Chrysler still chooses the 2 valve OHV path. That must say something about that design.