curve on it is very flat. it's actually rather impressive. IDK about MPG but I know me and my dad he has an 06 i have the 08. all things are same except for the year and on the highway I can easily just walk away from him from 40 on up. never went from a stop tho so IDK. can't see it being much different.

 

The advantage of the '08 4.7 over the '07 and earlier is the increase in power, more than the improved mpg. The improved in mpg is suppose to be fairly minimal, .5 to 1 mpg is all.