dually 4x4 milage

[robtoya]

I have a 2002 4x4 dually with 122000 miles on it. I've had it for about five months and have never had better than 13mpg empty on the highway. I've towed a 9000lb. toyhauler a few times averaging around 65mph and this has gotten me 8.5 to 9 mpg. Does this sound like there is something wrong with the truck or tranny? I don't consider myself heavy footed and the truck is completely stock. Are these dually's really that bad at milage? Does anybody know the axle ratio's on these trucks. Whay type of minor mods might help raise the milage? Thanks for any help/suggesstons.

 

[DaveBen]

That does sound like it is on the bottom of what you could expect for mileage. Check both of your filters (fuel and air). you might concider an intake system for a little more power and much better breathing. I don't know which ones are better than others, but I am sure someone will chime in with a suggestion.

Raising the gear ratio will help a bunch if you don't tow really heavy loads. Look on the driver's door post, below the strike post, for the axle code and post it back here and we can tell you what you are running.

Dave

 

[DaveBen]

Look in the Marketplace forum below, jvencius has an AFE unit tor sale that is a bit used. He is upgrading to another unit.

Dave

 

[HTRDDSL]

The duallys come with a 4.10 axle ratio.


If you upgrade the intake and exhaust you will definitely see an improvement.

 

[threejacks]

The duallys come with a 4.10 axle ratio.


If you upgrade the intake and exhaust you will definitely see an improvement.

My son's 2000 4X4 Dually came with 3.73 gears. I have 4.10 in mine and it is completely stock and I have always averaged 15 plus.

 

[Frankenstien]

I have a late 99 that came with stock 373, as I recall 410 was not Std untill 2005 when Fomoco upsized the Wheels to 18's.... as far as MPG goes... check the Link... below, if you look in the area that fits your MPG and check to see who has what... it will give you an idea if yours is even close to the Ball park... But from what I see your not even close to the Norm... unless you have other things going on that are not listed.. i.e lift kit larger tires...
Probably the Eastiest and cheapest mod you can do is to make yourself a Tymar type intake, this will help the Truck Breath conciderably easier, the next is to get a set of Gauges then a programer or Performance chip, this will help manage fuel to your Beast and keep thing in check, also will assit it in the Shifting department, next would be a larger free-flowing exaust.


http://www.superdutydiesel.com/forums/showthread.php?t=1559