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1998 Durango How to Improve Fuel economy

03-07-2004, 10:29 AM

I have a 1998 Durango SLT and Im looking to invest on some fuel economy enhancers... as you all know by now this trucks are awesome but they drink tons of gas. Im asking for some advise on what to get to get the best results... I will appreciate any help



03-07-2004, 01:26 PM
Mine has the 360 engine and was getting about 12 mpg. I installed a Jacobs electronic ignition, a K&N air filter system and switched it to Castrol synthetic oil and now get about 14 to 15 mpg. Don't know that the expense was worth the increase though.
I have always loved the way mine drives and handles compared to all the other SUV's but it does love gas. My son has the Eddie Bauer Explorer and it is aweful in comparison.

03-07-2004, 10:13 PM

I have the 5.2 L SLT, how much did you pay for the electronic ignition? also have you or anyone else heard of the HELIX THROTTLE BODY SPACER apparently add on 5 MPG with this bolt on piece... check the website and give me some inputs... Im about to order one and try... any ideas...


03-08-2004, 09:59 AM
It's been a long time but I think I paid $400 or so for it directly from Jacobs. It was one that they had used in some testing but still like new. I had to build my own bracket to mount it and the coil that came with it but it was still a pretty easy install. I think I paid about another $100 for the K&N filter kit.
I would love to find another 5+ mpg but don't know that it is possible without some major changes.
I have seen many devices like the throttle body spacer and don't think much of them. They started hitting the market way back in the mid 70's with the first oil crunch. I have doubts that any of them work very well if at all. What does it cost? I looked and saw no price listed for it. There is also the Vortex gadget that has been advertised on TV at times. I wouldn't think it would do much either.
What is your mileage with the 5.2L engine? Most I have heard of get 14 to 16 or so or not much different from my 5.9. My father in law has been buying Ford F150's with all the luxuries and has had a new one every year or two for his last 5 trucks. He never gets less than about 19 mpg with them. His 2004 has the 4.6L engine, is the full crew cab(4 door) and drives like a dream, has plenty of power and still gets 19 or better. When driving it, it almost feels like driving an 18 wheeler, it feels huge. I may even buy this one when he decides to trade again.

03-09-2004, 05:54 PM
The throttle body spacer is selling for like 137$ but I bought of ebay for like 40$ plus shipping, just waiting on it to see if it works, I dont know if I want to pay 400$ for the ignition computer, any good chips out there worth buying... thanks for the reply!

03-09-2004, 10:11 PM
Hope the spacer works for you. let me know for sure if it makes for any gas mileage. I have read of a few performance chips and some even help gas mileage a little bit but can't remember where I found them. Do a Google search and you should come up with some. You might look at and see if they have any. I have bought a few parts from them including my K&N kit and was very happy with them.

03-15-2004, 05:47 PM

I just got my space throttle but havent installed yet so I'll let you guys know what happens next week when I get to it..... also just tought I let you know I found this website with this item called the Fuel Atomizer apparently it increases the miles per galon for up to 50% but I spoke woth them and they said it averages at 40% which is still pretty good to me, thats like going from 12MPG to like 20MPG I can live with that :)

I ordered it and it should be here in about 2 weeks, when it gets here I'll post again to tell you if its good or not.... their website is pretty good you guys should check it out...


03-16-2004, 02:01 AM
The vaporizer thing sounds quite interesting. It is pretty close to an idea I had back in the mid 70's when gas first went so high and was even hard to get at times. I never found the money or machinery I needed to build it but believe I could make any engine get close to 100 mpg or better. All I need is a few hundred dollars in materials and free access to a good well equipped machine shop. I have always thought it crazy to run any engine on raw liquid gasoline. It is so inefficient.
I am also still interested in any gains you might get with the other thing too.
I just got back from Savannah, GA driving my sons Explorer. At least it gets 18 mpg or a little better on the road and that was running about 80 or faster most of the way.

04-02-2004, 01:07 PM
I do not mean to jump into the middle of your conversation, but, how did the fuel concepts device work??? I have an 03 R/T and I need to sqeeze out a few more miles to the gallon as well.


04-02-2004, 01:57 PM
I heard from other forums that those helix and similar spacers does not work on most 5.9's. On the 4.7's and maybe 5.2's there was just a very small improvement. Around 15-20 percent at best. It may have to do with the different type of intake manifolds that the 5.9 uses vs. 4.7's and 5.2's.

04-02-2004, 08:48 PM
Hey guys, I did some research on the magnetic "Atomizer". As it turns out, they are only about half there, and they use very poor magnets. They clamp around your fuel line and are supposed to cause the fuel to expand faster when it comes into contact with the air. This might get you a 1% increase in milage. I read the testing of the original concept and things were a little different. Gas milage went up as much as 37% with all vehicles increasing at least 17%. Since this was in the 1980's, none of the vehicles were fuel injected, so who knows if it will work on newer vehicles. Here it is: You need a minimum of two large Neodymium (rare earth) magnets and four small ones. The two large ones go on your air intake and the four small ones go on your fuel lines. You HAVE TO find out which sides are positive and which are negative. Just attach the big ones to the inside of the air intake with small bolts and attach the small ones right to the fuel line. The trick is to cause the air coming in the go through a powerful positive charge, and the fuel to go through a powerful negative charge. Opposites attract and the fuel mixes better than before. I know it sounds crazy, but if anyone wants more info. just e-mail me at I think I am at 19 MPG right now. I plan on cleaning out the cat. converter to pick up some more. ALSO, if I use regular fuel, I get 16 MPG. 3.15 gallons per 20 gallons are saved, so at $2 per gallon, I save a total of $2.30 on 20 gallons. If you try it with a full tank, you'll see what I mean. It's just so hard for people to give that extra 20 cents per gallon. Thanks!

04-04-2004, 10:38 AM
Where did you get the magnets and what was your gas mileage before you added them. I know there are may ways to increase mileage but like everyone else I am looking for the cheapest and most effective improvement. Do you know anyone who has put a K&N filter on? What about the K&N system that replaces the whole intake system??

I may have to belly up to the pump and try the premium gas for a tank or two.

04-12-2004, 08:54 PM
Well, I got my magnets through This is one great site for the electronics buf. They have literally millions of surplus electronics items. I had a total of about $20 in the 6 magnets that I used. The two big ones were $5 each and the small ones were $1.25 each. Believe it or not, that is an awesome deal for these magnets considering that they are the most powerful permanent magnets on earth (rare earth). Those things are unbelievably tough! You will have a hard time drilling through them, but it is a MUST for the big ones because they will stick to everything. It looks like they are out of stock on the ones that I bought, but any nice sized ones will work (like CAT# MAG-78 for air intake). You can even get bigger ones on eBay, but be ready for a bigger price too. The fuel line magnets will be easy to get, just get something like one inch long by half inch wide by 1/16th thick. I'll try to look up the website again so you guys can read the same article. As far as how much I increased, I'm not sure. I have always used premium fuel and I just checked gas milage after I put on the magnets. Ours is a 4x4 and I'd say that if we drove interstate, we could probably get 20 MPG. I am sure the magnets helped a little, but if not, I'm out $20 I guess. If anyone has any luck with the wind tunnel devices, please let us know! Thanks again!

05-22-2004, 03:52 PM
Ok, finally got my K&N intake installed with the Throttle body spacer. I have been driving it for 2 weeks and I must say I feel and see the difference, before,, by the end of my normal week I would be on half the tank and now Im in the 3/4 per week, to me thats outstanding...

I see some guys here got confused with the Magnet thingy, I also bouth that but when I got it it seemed too cheap and didnt install it.

Now back to the atomizer received the kit and when I went to install it notice I dont have a fuel return line!!!! I need this line because is where the atomizer gets its fuel from, second alternative is to buy a shredder valve kit which lets you tap into the fuel supply line and it closes the valve so when you turn off your vehicle it doesnt flood it,,,,, so Im going to order the shredder kit this week and as soon as I get it I will install it and let you guys know, I had everything already installed except for the fuel line and it took me like 30 minutes to get it all ready so it wont be long before Im saving gas,,,

Like I said I'll keep you posted...

06-04-2004, 08:06 PM
hey you guys all talk about mileage i've never even seen. i have a 4.7 liter durango and i only get 13 - 14 mpg with a cold air intake from airaid. Tons of power but thirsty. I baby it most of the time and mpg never improves. any thoughts?

06-05-2004, 03:16 AM
I think we built these things, so we should be able to get better mileage out of them without using scientific magical magnets...

Not saying that they don't work, but there must be a better way, like come on!

06-11-2004, 09:16 PM
hey you guys all talk about mileage i've never even seen. i have a 4.7 liter durango and i only get 13 - 14 mpg with a cold air intake from airaid. Tons of power but thirsty. I baby it most of the time and mpg never improves. any thoughts?

I have a 00 Durango R/T and replaced the paper air filter with an K&N filter but still using the stock airbox. Don't see how a cold air intake setup would give any better result as I see intake side of the stock airbox is ducted thru the side of the truck so it won't be pulling in hot air from the engine cabin. I noticed about a 1 mpg improvement but that's it. Best I can get on this thirsty 5.9 is 10.5-12.3 city and 13-14 on the highway. Those numbers are based on a super light foot. I hate to see the numbers if I got a lead foot. Haven't found anything else on the web to help increase a couple more mpg's on this 5.9 without spending more in money than you would get in savings on gas mileage.

06-18-2004, 11:45 AM
Well, for you guys that just joined the topic I suggest you read from the beginning, I recommend the Fuel Atomizer 2000, even though I havent try it yet because Im waiting on a shreadder valve kit (this is needed when you dont have a fuel return line which is all of us) as soon as it gets here I ll through it on and see the increase it should be some where between -6 MPG increase.

I was also doing some research on it and this fuel atomizer sucks the oil sludge out of the engine and puts it on a little jar outside the engine so that you can change it on every oil change,,, yup two birds with one stone.... you know durangos are infamous for the bad engine compresion and dyieng while running due to excesive sludge on the oil pan so this products if it works like it should it will save Gas and the engine itself... anyways just keeping you posted, the valve should be in by the end of this month and then to me a week later so as soon as I get my hands on it I'll let you know how it went...

A comment on the cold air intake, I have a K&N filter/ Intake and trust me it does makes a difference compared to the box with just a replacement filter, when you installed the cold air filter/ intake it does not have any kind if restrictions whatsoever and part of the install process is to remove a piece of like cloth that seats behind the front grill, this lets the air from the road come straight into the filter giving you that extra cold air power, I know my Intake in combination with a throttel body spacer gave me an extra 3MPG on the city and 2 extra on the Highway, I got a 5.2L SLT thats like 15MPG city 17MPG High Way,,, talk about some money in your pocket... anyways I'll let you marinate on that... :)

good luck on your saving gas race...

06-18-2004, 11:54 AM
I'll wait until you get the results of your atomizer thing. As far as the spacer goes. From what other users have responded to it. The spacer does not have any affect on the 5.9 engines. At least from 3 users that had used it on a 5.9. However on the 4.7/5.2, there was a small improvement. My guess is the different intake manifold design.

I started a thread in the about what to get to get a little more power and possible gas mileage from a 5.9 Durango and so far, I got some good responses. I am sold on the fastman throttle body upgrade. Some users said upgrading the intake manifold will breathe more power for the 5.9 as well as small gas mileage improvement. Once these 2 upgrades are in place and I see a small improvement in gas mileage, I'll opt for the cold air package to maximize the 5.9's breathing. Have any of you checked out Mopar's performance stuff for their Magnum engines? Thinking of going all out on Mopar to keep the factory appearance under the hood. Mopar makes a cold air package similar to K&N but has the Mopar badges on it. They also have headers, and especially the Mopar M1 intake manifold upgrade that caught my eye after alot of Dakota R/T owners gave it some very good reviews. If any of you dodge owners aren't aware of that new forum, check it out. - Strictly for chrylser/dodge addicts.

10-18-2004, 04:12 PM
rod2envy please update us on your experience on the Fuel Atomizer 2000. Is it the real deal or snake oil?

11-12-2004, 02:30 PM
I just bought a THROTTLE BODY SPACER (for my 99 5.2) on ebay for $30!... but the instructions that came with it are a crappy ass poor quality unreadable photocopy, thats says basically;"
unbolt the throttle, clean off old gaskets, place in the spacer and the new gaskets, re-bolt."
I'm not very mechanically savy, but I can turn a bolt.

Does anyone have a link or diagram ... maybe a better explination of where exactally this goes and how to do it?

Will I need a tube of gasket sealer or are the discs that were sent in the kit sufficiant?


here is a link to what I bought;

Ok, finally got my K&N intake installed with the Throttle body spacer. I have been driving it for 2 weeks and I must say I feel and see the difference, before,, by the end of my normal week I would be on half the tank and now Im in the 3/4 per week, to me thats outstanding...

Like I said I'll keep you posted...

11-17-2004, 11:46 AM
This message is part to bump this topic to the top and also to ask what people first recomend for fuel efficiency. I have just purchased a 2002 sxt Drango and want to know what there is for improving fuel. Is there any improvement that people notice from the mid to late 90s vs 2000 years? I have heard about the chips that make the engine think it is receiving more cold air than it actually is... is this good for the engine?


11-25-2004, 08:47 PM
I have recently started to put Lucas fuel injector cleaner in my truck. The lucas also lubricates your entire fuel system including pump. It pays for itself in mpg especially if you buy the larger econo size. I also notice a difference in power and smoothness. More power and smoother operation for free! Can't go wrong with that.

11-26-2004, 07:45 PM
I have the 5.9 liter, 9.2 rear end. I have been averaging 15.0 mph, but a lot of driving is highway. I put in a K&N filter; mileage did not seem to change, but it seems to have better performance.
Mine has been a great vehicle, with few problems.

05-28-2005, 08:17 PM
i have a 99 durnago with a 5.9 motor and it stinks on gas i get about 230 miles to a tank with it thats if i push it to [E] what can i do to improve my fuel economy i like the truck but hate what kind of gas mileage i get with it thanks

01-16-2016, 01:16 AM
Hey guys i have a 99 Durango 5.2 with the k&n cold air intake, 3" catback exhaust with Flowmaster 44. I get around 18 mpg with this but its still a dog off the line, I'm trying to get more ooomph out of it, i have a jacobs ignition box to put in it but no wiring instructions or diagrams, curious if anybody has installed one of these and how to do it.

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