I see that many of yo are experiencing the same thing I am aswell. I am averageing about 11 MPG which quite honestly is worse than I had hopped for. I am not overly complaining thoughas this is in the relm of what I expected and was hoping to avoid. LIke mentioned above I am tinkering with the idea of the Cold Air induction, an TBI spacer ( Jet/Air Raid/ Crane Cam) haven't figured that out yet, and maybe a cat back exhaust. I did notice though that my lead foot softened quite a lot since I bought this truck and I don't seem to be driving as hard or as hurried. This may be a great thing down the road.

Sea Thunder can you quantify what "It helped a lot" means? If you are getting more than 2-3mpg since the upgrades that would be good. Also why did you choose the Air Raid gear over some of the others? Did you do all the mods at once or in stages. If in stages did you see improvements before moving on to the next piece?


Ultimately this is going to be like driving my 69 Charger was...if you stay out of the secondaries MPG good, foot to the floor MPG bad.

 

i was having problems with my `98 5.2 , mostly a loss of power and slow response along with the typical bad fuel efficiancy. after talking to some friends who have street legal drag cars i came up with a list of improvements . the cold air intake is pretty much the easiest way to improve mileage and power. get rid of that bulky factory air box and get some air in there. the airraid i chose because choices are somewhat limited for durangos and it was more available. A better option that was reccomended to me was making a custom cold air intake running it to the front corner of the engine compartment and down by the bottom edge of the radiator . that way you get no heat at all from the engine just cold air. i did the intake first and it probably added 2-3 mpg by itself. i also noticed addded power immediately. next i picked up the helix throttlebody spacer. i chose helix because the design looked the best out of the ones that were available. that probably added 2-3 mpg also. plus increased powerboth of these mods are easy to install taking only about 30 min. each. i then picked up Taylor 8mm performance plug wires( just a note, i the wires came in a universal kit where you have to cut the wires to length and install the connectors and boots so a little more time and the right tools and some skill are required.) i also picked up NGK spark plugs . i had platinum plugs in and they do not work well at all , it looked like it was too hot for them. truck plugs i found are the best , champion or ngk were reccomended to me. i just filled up with gas and i`m tracking it right now to see what mileage i get out of it so i`ll update in three or four days and let you know what i get. Also my next step is to put a new exhaust system on my durango ,probably from the haders all the way back, so if anyone has any suggestions it will be greatly appreciated.

 

Seathunder thanks for the reply. That is the info I was looking for. What are you using as your baseline milage to test against? It would seem that if you are correct about the estimated improvements you should be seeing about 15-17MPG assuming 11mpg average. I could live with that...in fact that is what I was hoping for. On the issue of exhaust systems I am leaning towards the Magnaflow setup. Reason being is that it's not as loud as the Flowmaster or Gibson and may flow better according to a guy I work with who used to build performance street cars. I love the thick rumble of a V8, but I don't need it inside the cab so loud that I can't hear Van Halen on the radio. I did the whole listen to the engine thing in my 440 Charger for a while and loved every minute of it, but a tuned performance exhaust with a subtle rumble would suit me fine now. I drive a Durango not a Charger ( man I miss that car).

On the TB spacer issue I have been leaning towards the Cran Cams piece as it had te most published numbers for gains and a clean design, but If I go AirRaid might as well get the pieces that were designed for each other.

Looks like you and I are thinking quite a bit alike. Hope you don't mind me walking in your footsteps.[sm=smiley20.gif]

 

Don't waste your money on a throttle body spacer. Do the air box and the exaust systems. They are the only things that make any noticeable difference.

 

You can accomplish the same thing as a TB spacer by adding length somewhere else in the intake tube. A TB spacer will work on a TBI or carbuerated engine, but not on an MPFI engine. Since the Magnum V-8s are MPFI a TB spacer is a nice paper weight. The point of a TB spacer is to promote atomization of the A/F mixture, since the fuel isn't added until almost the Valves, then there is no A/F mixture. All a Spacer will do is swirl the Air creating more turbulence in the Intake Manifold.

 

I would have to agree with everyone about taking that foot off the gas. I drive mine like a granny because in california you can only go as fast as the traffic! I get between 10.3 to 11.5 mpg around town and about 17 to 19 mpg on a trip. Going off road is almost worse because I really see a change in the gas gauge.

 

After driving back from South Dakota I could watch the needle move on the gas gauge and still only avg. 13.9 that whole trip. Cruise control is crap.... but I tried a fuel addative and come to the conclusion I'd have been better off buying gas with the like 3 bucks I paid. But I'm thinking about the exhaust and the cold air intake.... I'd also think a new alignment and replacing most of my messed up front end would help too.

But that trip back solidified my resolve to never ever get rid of my D. Partly because it saved me from myself, I have a tendency to push the limits a bit and this was no exception on 90 East in MN it started snowing pretty good. probably about an inch 2 inches on the ground. like the previous 8 cars (mostly those minivans that are tangible evidence of evil). I decided to pass by about maybe 3 mph difference didn't even accelerate well hit a big big sheet of black ice and the traction in the rear went out. I started to fishtail probably about 6 times before she decided to spin out spun twice fishtailed diagonally across about 20 yards of grass median spun about 3 more times agross that highway and into the grass next to it. spun and ended up rear end forward. The fact I didn't flip it liek the 30 cars I saw on their sides or roofs the rest of the way impresses me and I subsequently did little speeding the rest of the trip. So thank you dodge for building a vehicle that I abuse regularly and takes it all instride.

Since that got me to lighten up the foot I get 12.7mpg now. Gotta scoot take it easy ya'll. (Yes I know I was doing soemthing I shouldn't have and please no one follow the example)

 

I run good bosch plugs keep the oil changed and have a air hog airfilter i get 13.6. My durango is 2wd with the 5.9.

 

I have the 5.9 and the gas milage computer says 15.7 as the average MPG. We haven't done anything to it mod wise but use synthetic oil and premium gas. Most people say there is no difference, but I get atleast a 2 miles per gallon further with premium fuel. The other thing that helps is keeping the vehicle well maintained as in tire pressure, alignments, and anything else that goes wrong. Also I do about 50/50 of highway/city driving, but am easy on the throttle.

 

Keeping the foot out of the gas is the best, but I like to keep it to the floor. Sure is fun!!![sm=badbadbad.gif] The idea of upgrades are always good tho [sm=happy046.gif] I know I love mine.[sm=icon_sneaky.gif]