Where else to better get an idea of what truckers want than on a trucker forum?

I am not selling anything, and these are honest curiousity questions.

First post here. I don't drive a truck - I design transport systems. I'll go into more detail on that if you wish.

Can you please help a complete novice in this field?

1. What is your average Miles Per Gallon?
2. Are fuel costs one of your top three concerns?
3. If a new model truck came to market that was completely different in design, and all other aspects being equal, at what MPG (a number please) would you seriously consider replacing your current ride? (Note, obviously everyone wants 100MPG. What is the LOWEST number, off the top of your head, where you would say "I simply MUST look into this"?)

4. Cab/view height - Please pick one - a. Must be as high as my current ride, b. I would like it to be at passenger car height, c. It doesn't matter, or d. Other - explain

I really appreciate your input.