YES i've finally done it sence i modified my air intake my 98 dakota 4x4 with the 5.2 and a 5 speed manual it is getting 18 miles to the gallon instead of 14 or 15. i know i should probably stop here but does anyone think headers would be worth it? i've heard they up your gasmileage and horsepower. i've already got Dual exhaust but its a Y pipe and it has a glaspack on it and a performance cat that you can basically see thru so my exhaust breathes really good so would headers make any difference in power and fuel mileage? and also if they would does anyone know where i can get a good set for reasonable price?

 

i have the same truck you do only a 1999. i am getting 21MPG at 70MPH on the freeway with an automatic. i think you would see more bang for the buck with an under drive pulley. it slows down your accessories and reduces drag on the motor, supposed to be good for 15hp or 2-3 MPG and its about $50. then move on to some headers. im looking for some headers now. summit has some shorty's for like $150 but they are only good for 15HP while full length headers are good for 40-50hp but cost at least $600. when i was buying my truck i searched high and low for a v8 with a stick shift and couldn't find one in the whole country for any price..

iridium plugs
new stock replacement wires
air raid intake
summit under drive pulley
31" tires
Leer bed shell (i think some aerodynamics might be helping)

 

My buddy is selling his 98 ex cab 4x4 with a 318 and 5-speed, just over 100k miles I think. Asking $10.5, with rhino lining, canopy, RT 17" wheels and brand new tires.

Should have waited just a little longer.

Iridium plugs imho are a waste of money. They're supposed to give the power of copper with the longevity of platinum. I can understand using them on a Subaru or Porsche with a flat 4 or 6 where it's a major PITA to get at the plugs, but in these things? It's too easy. Plus if you change your plugs every 15k or so miles it gives you a reason to check the air filter, pcv, brake fluid, power steering fluid, tranny fluid, etc.

Plug wires, if they're old, are always a good thing to replace. OEM ones are fine, thicker performance ones will conduct better and give a better spark.

Air raid intake or K&N - they're expensive but apparently they work.

Underdrive pulley - get one with the harmonic dampner built in, or plan on engine problems in a few years

Tires - get tall skinny tires with highway ribs for best mileage. Mud tires hurt due to wind and rolling resistance.

a canopy or bed cover will help mileage, but if you don't have one, leave your tailgate up. Some people think having it down decreases drag, but it really just increases turbulence in the air going over the truck, which increases drag.

 

I have always liked the soft bed cover over the hard ones and they help on gas a little.

 

how much would you say the soft covers help? im looking for one for my 99 club cab short bed(its like 6 feet, i think thats a short bed) any suggestions on a cheap brand? anyone try truxedo? i want one for the winter up at school in duluth minnesota so it has to be able to withstand a couple winters.

 

20 MPG? Wow, the best I get is 15.5 on the road and 13.5 combined driving. 99 Dak with 5.2 auto, 4x4 lifted with 32" BFG ATs. I installed shorty headers and noticed an immediate improvement in grunt throughout the RPM range. I would say a definite yes to putting shorty headers on your rig. I have a soft tonneau cover that seems to slightly help the mileage. I've got a TB spacer, Edelbrock air cleaner, MSD, Acel plug wires, hyperspeed O2 bypass, and superchip tuner. The only dud in all of that was the TB spacer, I couldn't tell much difference with it. Based on some of the posts, I may try the speed reduction pulley. They worked good on my Mustang, should do the same for the Dak.

 

bought my 99 with 50k miles on it with the 4x4, kick *** component stereo system with 2 amps and a pair of 10" subs, 31" tires and the bed shell for the same price :-)

the pulley attaches to the stock harmonic dampener, i got the air raid intake for $65 (eBay!) and iridium plugs kick ***. i got about 80k miles out of my last set of iridium's (as opposed to 50k on platinum's) and it really does make a driveability difference. while they may or may not make more power they make for super easy starting and they seem to burn better. i ran my last set in my ranger and after 140k on the odometer i pulled the head and everything inside looked brand new, zero carbon buildup on either the valves or the piston. also run a set in my ninja and they made a world of difference. most sport bikes come with them stock now. my wires were leaking some electronic noise so i changed em out and did the cap and rotor while i was at it.