I had a 97' that got 12-13 pretty consistantly. It got 9-10mpg when I bought it, but new plugs and wires got 1 mpg, k&n air filter gained almost 1, and cleaning out the air pump filter for the catalytic converter gained another 1 mpg. Doing doughnuts around my mom's car dropped the mileage about 80% and cost me lots in gas and tires, but man was it worth it! I like my 03 hemi that gets 13-14mpg just as much as the 97', but the v10 was paid for and you can buy a lot of gas vs. getting a "more efficient" truck like I did.

 

HI,
I just bought a '99 Ram V10 - 4.10 diff. 4X4 - Auto. Only 81,000 mi. The digital display goes to 8.5 - 10.5 and once 11.7 driving back to El Centro from Phoenix. 0-500 ft. elevation. I just manually checked mpg first time. 155 mi. , 27 gal. Only 30 mi. while pulling my 10k lb trailer. I am getting 5.7 mpg ! I do have 2- 90 in. toolboxes on the top bed sides and a coupe bins for more tools totaling about 800 lb.
What this proves is that the digital calc. is WAY OFF! I see in all the posts about mpg that no one mentions if they are just looking at the digital display. Using 9.5 vs 5.7mpg this is a 40% discrepancy!
I replaced my '97 f-250 - 460 gas which got 8.5 - 9 pulling. 3.55 diff. ( w/ 1,400 lb service body and topper plus cargo.)
Well, I wanted more power as I live on the road pulling my house. (As little as possible) . I cancelled getting the diesel because of potential huge parts-maintenance costs.

 

With a 488 cube V10 it's more a 'gallons per mile' than 'miles per gallon'...