Hi, I just picked up a 00 Dakota 5.9 and I love the truck, but she sure is thirsty! All it has done to it is a Magnaflow Dual exhaust, been thinking about a cold air intake, and possibly a programmer. I know the truck isn't made for fuel economy, but if there is anything that would help out and give me a little more power that'd be nice. I saw the Matrix air intakes on Summit Racing, for only $80 and I wondered if they're any good? Thanks for any help!

 

the 5.9 is a thirsty motor.. i would def try the cold air intake..you may pick up a few miles a gallon with that,and also increase in the power department

 

not much cheap stuff out there to improve mileage. It is usually HP mods that add mileage lol.

Larger TB
3 or 5 point valve job
shorter duration cam (low end torque and mileage woot)
replace clutch fan with electronic
180* t-stat
remove A/C

That's all I can think of off the top of my head.


Oh yea, don't forget a 408 stroker kit >:]

 

How bad is it on fuel??? Are we talking low teens or in the single digits? Mine is an underpowered slow *** V6 which barely moves the truck without putting your foot into it and gets around 15 mpg. Ouch! So if you are near that number consider yourself lucky cause at least you got the ***** to make er go. And as said above, a cold air should help a small bit with mileage. Good luck and i'll see you at the gas station.

 

13-14 average, 15 if I go reaaaaaaaaal easy on it haha. I think I might give the CAI a shot, thanks guys!

 

Cold air shouldn't help, cold air makes you burn more fuel. Technically it should decrease MPG, but it may no if there is another factor. Almost everything you buy will not pay for it self unless you own the truck for ever. But if we are talking MPG's you can do the following...
Bed cover, remove extra weight (spare tire, fat wife, etc), E-fan, and a few more. Those will probably give you the best MPG for the dollar. Maybe 17mpg lol. I actually just bought a small 600 dollar car that gets 40mpg for the weekdays and I use the truck on the weekends. Also, driving slower will help MPG's. Just saying.

 

Cold air is denser, and CAI are less restrictive which gives more intake velocity, cramming more are into the cylinders, the computer will read this and inject more fuel, giving more power per stroke. More power = less strain, same reason a 3.9 will get the same mileage as 5.9. The 5.9 may burn alot more fuel, but it does so freely, without strain.

Bed covers don't help, there is a low pressure bubble formed behind the cab when you drive. A cover will not change this.

Also, driving slower does not necessarily mean better mileage. RPMs are more important than speed. The only effect speed has on mileage is wind resistance, which although is alot at 70mph, is still superceded by other factors such as computer programming, gearing, road grade, and CAMSHAFT specs. Your cam is one of the biggest factors that control the power curve. A person in my off road group informed us that based on his power curve (dyno tested) he gets better mileage doing 70 than 60, and it checked out in the real world. And although we may not have the aerodynamics of a corvette, Jeeps are even worse lol

 

Bed covers help, I will not explain because I feel that this is the wrong forum to talk about it. True about the cams and speed, but assuming you had a CVT driving slower will always yield better MPG.

EDIT: Also, your statement "the only effect speed has on mileage is wind resistance" is horribly wrong. You have friction in your tires, dif, transmission, and engine. All go up with speed/rpm. Yes, sometimes driving faster is more efficient. But this is due to gear ratios and peak engine efficiency.

To the OP, take off your passenger mirror, I know it's crazy but it helps.

 

Drive with tailgate down helps, It's not how fast you drive but how you get up to speed that counts. I'm looking at getting smaller sport type mirrors and narrower front tires to help with mine.

 

You are right. Tires can be changed. The only thing you can do about engine, differentials, and transmission though is go to a high quality synthetic. I recall reading somewhere that a vehicle with royal purple throughout got ~10hp gain over using conventional oil. That would help, but royal purple aint cheap at all.