1999 3500 mpg

Hi I am new here and was hopeing you could help me. My dad has a 1999 Chevy 3500 454 (7.4) automatic with a 12 flat bed. I figured it out the other day that i was only getting about 5 miles to the gallon. I went 56 miles on 13.5 gallons!!!!:crying: Well the truck recently got new a new filter and plugs. I was mainly wondering if you guys had any other sugestions to help with the millage.

Also I was thinking about getting some aftermarket for it also.

Tornado Air System - Up to 3 mpg 51.99
Mass Air Flow Sensor - 15 hp and up to 2 mpg 279.20

what are you opinions?

Wow! I don't have anything that I could tell you that would help, but that is definitley really bad MPG! I have a 97 1500 with almost 300,000 miles on it and I can go around 350 miles on a single tank! Give or take some depending on the speeds and location of course - but wow.

I gained a few mpg from having a tune up, on highway 100 miles in no stop and go traffic burns about a quarter of a tank now. :)

What exactly did you do for the tune up? And the truck only has 105,000 on it!!

here's about the only and ultimate source on mpg:
http://peswiki.com/energy/Directory:Fuel_Efficiency

Tornado - NO!!!!
K&N air filter - yes. don't expect much though, maybe a mile/gallon
HALO plugs - YES!! i have them tested myself on several cars.

as of your mileage - well, for 7.4L and whatever else you doing with it - it's almost about right. excursion was listed for 8mpg, and that was an over estimate. it's a big, heavy truck, you know. yours. should have worse mpg than excursion.