With the price of fuel at an all time high, I am looking to get the most economy out my 1999 5.9 liter Durango. I was wondering if anyone has changed the factory installed all terrain tires to a less aggressive mud and snow tire of the same size and will this improve to mileage. I do plan on changing the exhaust to either a dual or free flowing cat back still trying to figure which is the best way to go. Any other advises as to changes that would be beneficial would be appreciated.

 

I'm not much on the tire thing but, Dual exhaust will gain a little more H.P. not sure about saving gas. I would make sure you keep the oil clean and change air filters regulary. O2 sensor also. That's a very good motor u got there! R.V.

 

If you want to improve mileage on the tires part, research and buy a low rolling resistance all season tire instead of an offroad tire! Any offroad tire will have a much higher rolling resistance than a highway all season tire. Higher resistance, less MPG's.