Originally Posted by thetrader50

OK i have a 2003 durango rx was getting 14 miles a gal.I put a performance chip on now i get 17 1/2 miles to the gallon.

Originally Posted by redfernclan

For what it's worth, I bought my 98 4x4 with a 318 new. After about a year, I got tired of the poor mileage. I talked to the local exhaust/hot rod guru about putting on 3 inch exhaust. I had done it on my 91 Dakota and it made it fly! We talked about many options and I left it up to him to decide after he got up in there. When I picked it up he said the stock exhaust was actually pretty free flowing and he couldn't see cutting out all that stainless pipe to be replaced with galvanized. He stuck in a 3 inch WalkerDynomax and went three inch out the end. I put a K&N filter in to replace the stock one. I did not go as far as the cold air intake. I also added an "RV" or "stage 1" chip, whatever you want to call it. The main reason I did this was that I wanted to put a shift kit in the tranny and in doing my research, I found that in this day and age, you just "chip" it. B&M doesn't, or didn't, even make a kit for it. I did this over the course of a month and drove it daily to see how much each mod made a difference. The biggest difference was when I installed the chip. It gave it a much quicker throttle response. I don't have a lead foot so I really didn't notice any other difference other than sounding really cool.
They way I look at it, if my motor is rated at 210HP and I increase it to 225HP, the only time I'm going to see it is when I would have used the 210HP up and ran out of ponies. ie-full throttle, giving it all shes got. I just don't drive that way anymore. What I did see was about a 1 1/2 mpg increase in mileage. I'm not swearing to it and it could simply be my driving habits subconsciously changed in try to get better mileage.
Be that what it may, it spends most of it's time parked now and is our tow vehicle. I have 32 inch tires on it so in checking the mileage, it will be off a little. I'm doing good to average 12 to 13, but that is pulling half the time. When I had the stock tires on it, I would average about 15 to 16 day to day going to work. That is combined highway and city. I would get 20 mpg on the console read out, on a hot day, after driving half an hour, while doing 55 mph. Go 65, you kill the mileage. go through a couple of stop lights, you kill the mileage. That 20 mpg was "real time" and didn't take into account even the fuel that was used to get up to speed.
That would be my experience with Durango and mileage. We didn't buy it for the economy.

Originally Posted by hydrashocker

I deleted the spam and had to alter peoples posting.



A chip/tuner cannot alter a hydraulic transmission so it did nothing to it. Only a Shift Kit can alter it. Transgo makes a kit for you and is what you want. B&M doesn't make a kit for anything over a 1994 I think.

One issue with a chip is the PCM learns it and slowly changes the running parameters. One thing you can do to combat this is reset the PCM ever so often. A PCM tuner fixes this issue because it actually changes the PCM's parameters.

The console read out is never right. You have to do the math with gallons used and mileage ran. Concitering you are running oversized tires it should be lesser as well.