dan55, i read in your bio, that you are a newbie..here, as well as a driver too..?? or are you a student in a driving school right now..???
if this is true, then try not to even get involved with what truck to buy for a long, long time.
if trucks are getting 'up to" 10 mpg's today, then into the future that'll go up a bit more.
if you are a newbie to driving, or a student in school learning to drive, and i think you are, since you asked about freight brokers, then concentrate on your learning how to drive, then get a job, do the job, gain your experience, then if you are still in this industry, and want to buy a truck, in say about 2 to 5 years from now......then inquire about truck fuel mpg's, but by then....you'd have enough experience to either continue as a driver, or you'll be out completely from this industry.
right now, as a newbie, what mpg's a truck get's is just not important..