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I Have A 1999 2500 4wd,superchip,straight Exhaust,k&n Filter. My Problem Is The Best Milage I Can Get Is About 17.i Have Replaced The Vp44,put New Stock Injectors In.i Have Tried The Superchip On All Three Settings.i Run Additive In The Fuel,i Have Tried Them All!i Have Worked On Diesels For 22 Years,so I Thougt I Could Figure It Out,but No Luck!my Step Dad Has A 99 Dually 4wd&he Has The Same Problem.also Both Trucks Have A Hard Time Keeping The Fuel Pres. Up.under A Load They Both Will Flicker The Warning Light.mine Has 2 Stock Pumps & A New Draw Tube.his Has A Tank Pump&stock Pump. Thanks For Any Ideas,ron
 

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what mileage do you get now?
your fuel pressure problem can be solved by a better aftermarket lift pump. airdog, fass, etc.
search those names and you'll get all the info you can handle!
 

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How fast are you going? Is this city, highway or combined? My 04.5 gets about 18-18.5 combined so 17 is not totally out of the norm.
 

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17 MPG for an average isn't off for an auto trans. The manuals will squeak a few more MPG's. Keep the top speed under 65 and the EGT's below 600 while accelerating and you may squeak a bit more out of it..

Ditto on the aftermarket lift pump. Dodge has nothing to offer lift pump wise worth buying.
 

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The auto gets a different engine in the old 24 valves vs the 6 speed, too. I am sure that plays into the fuel efficiency. The six speed gets an engine with a 17:1 compression ratio versus a 16.5:1. I think bigger fuel fittings, different intake horn too.

17 mpg really isn't too bad. Especially if you do a lot of stop and go/in town driving.
 
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