This all makes a lot of sense. Perhaps I am completely wrong about this whole concept. If you bear with me, I just have a few more questions on the subject.
I don't know why it didn't click before, but you are right:
The amount of fuel (or energy) it takes to push the car through the air at any given speed is not going to change. This makes sense to me, I just have a few questions.
Can you enplane how VW got more power from the ECOdiesel then with the N/A diesel? I would assume the only way they could do that was to have the fuel pump set-up to inject more fuel then the N/A version. Except that when it was not under boost it would be running rich, which I don't believe VW would do because the main purpose of this car was low emissions.
Perhaps this is going over the basics a little too much, but play along with me here.
I am wondering about the difference in power/fuel usage between Turbo Vs. N/A diesels.
The N/A diesel can cruse the same at 55mph that the Turbo can. The Turbo can make more power then the N/A at a lower RPM, but assuming that the Turbo and the N/A are geared the same so they are running at the same RPM at 55mph. To achieve the greatest efficiency is it better to have an N/A diesel or a Turbo? Or is it safe to assume that the Turbo and the N/A are using the same amount of fuel (or energy) at the same RPM to move along at 55mph?
Now I don't think they use the same amount of fuel, because if they did they would have the same MPG rating.
The '85 Jetta diesel is EPA rated for 41 MPG Highway. While;
The '85 Jetta turbodiesel is EPA rated for 38 MPG Highway.
I wish I could post the page where these two cars are compared next to each other, but that is not how the website is setup. Though the information can be found here:
http://www.fueleconomy.gov/Feg/findacar.htm
Assuming they are using the same amount of fuel (or energy) at cursing speed, is the Turbo getting worse mileage then the N/A because of the exhaust gas restrictions caused by the turbo itself? Or perhaps the Turbo was a higher trim lever and had luxury options and such causing more weight?
I am really not trying to be a jerk rambling on about this, you guys are obviously well versed on diesels and I just want to further my understanding.
These things seem like discrepancies in the thought process to me.
Thanks!
Eli
P.S.
Thanks for pointing out that I was wrong about the lean mixture meaning overheating. I read that somewhere, someone mentioning it in reference to diesels. I do not want to be one of those people spreading false information.