Help me make a decision

If you drive it right, depending on what rear ends it has. You can see 6.5 - 7 with that Cat. Just keep your Rpm's where they need to be, usually around 1350 - 1450 depending on the rears and speed. If you run it over that your fuel mileage will continue to drop for every 100 rpm that you go up.

 

Hi kabusheke, the Frightliner Century I drove had 3:55's, 13, and small rubber and that thing, you'd grab the last gear @70. 230 w.b. is a good number. Nice ride and can still get around pretty good. (that Freightliner was a 230)

 

You should be ok, with the RPM's that I described. you will most likely average between 6.2 - 6.5 when driven correctly. Stay away from Bio-Fuel if at all possible, carry extra fuel filters to change out when you get the crappy fuel, filters are cheaper then fuel. Go for it and keep up on the little things and she will make you money.