what does you rpm's read at 60 mph and at 75 mph?

That is dependant upon size of truck, engine size, transmission type and rear end ratio.

either way they will be close i am just looking for what other have for rmp's I have an 02 limited explorer with 4.6 and at 60 i get about 17 mpg and at 75 to 80 about 14 i am just curious what rpms people are getting at these speed and roughly the mpg to. thanks