I recently bought a '98 Dakota Sport with 2.4, 5 speed, and 98,000 miles on it. I noticed it was sucking up gas really fast so decided to tune it up a bit; here's what I did: New spark plugs (Champion), wires (Bosch), cap & rotor, and the front o2 sensor. I had also run a bottle of Techron through a tankful, did an MMO piston soak, and cleaned out the TB with brake cleaner. She runs like a top but gets only 8.66 mpg!! I don't know where to go from here, or what to check next, and was hoping you guys could give me some ideas. Also, what kind gas mileage should this setup be getting? Thanks for any help you can give me. Almost forgot to mention - most of the driving was in town with the ac on, but driven easy and coasting as much as possible.

 

You didn't mention air cleaner, did you replace the air cleaner? What did the old plugs look like? Were they sooty black (running too rich)? Do you get any black smoke from the exhaust (running too rich)? Could also be a clogged up catlytic converter.

 

OldDodgeDriver, thanks for your response. The air cleaner is fine, and the cat was replaced about 6 mos ago because it failed smog. I believe that the plugs that were in it were the originals as I've never seen plugs worn that bad, but they were not sooty. I've pulled the new plugs a couple of times and they look great; no soot. No black smoke. Very confusing. Do you have any other ideas? Anyone else? Thanks, Dave.

 

i think what you are not realizing is that you have an extremely underpowered motor in a relatively heavy truck. i have a 3.9 v6 and get about 14 mpg. the v8 model gets the same and even better mpg that i do! the problem is that your i4 does not have enough power to effeciently move the truck. as a result, you use much more gas than expected. everyone thinks that have an i4 will save you in the mpg area. this is true, unless you are using that i4 in a way that is very ineffecient; this example, moving a truck weighing between 3481 lbs. and 3733 lbs. depending on cab model. make sure you have no blockage of air flow in and out of the motor, as old dodge driver said make sure you are not running rich, get a new air filter (hopefully a k&n), exhaust, maintain proper tire pressure and check out small mods listed throughout this forum. i see that you did a tune up and that is a great start. i wish you good luck and hope the mpg gods look down upon you with grace!

best of luck


chris

p.s. keep us posted on how it works out for you!

 

probaly not the case, but my old friend from high school tried to explain to me he was getting over 100 miles per gallon in a 4cylinder jeep. don't know what kinda mathhe used to get that # but are you doing your math right? ie. total mileage/22 gallons. or may be you have a leak somewhere. you never know. that truck should be getting 20-25mpg.

 

Thanks Chris, I have considered all that, but 8.66mpg?? I just called the dealership and they said I should get 13-15 around town and 17-23 hwy. I think there's gotta be something wrong that I'm overlooking, but what?

 

your friend was smoking crack instead of going to class if he thought he was getting 100 mpg in a jeep. i think this is the equation he was using:

total milage/22 gallons x 10 + crack pipe = 100 mpg

 

How about brakes, any chance they are dragging? If everything in the engine, fuel and exhaust system check out, maybe its extra drag creating problems? Notice extra hot pads or drums when you drive? I'm stumped cause you should be getting better mileage than that, 4 cylinder or not.

 

i can't remember very well but i think i did smell somthing in the air[sm=guilty.gif]

 

hahaha