All three of my TB sensors are stocker originals. 203,000+ miles. In fact, every sensor EXCEPT my front 02 sensor and rear speed sensor are stocker originals.

At this point, I'm fearful to change them LOL. But you can see why I am a huge OEM sensor fan.

IndyDurango

 

I just finished sucking up my tank of fuel. With the new O2 sensor in place in conjunction with the new map sensor, I would have to side with PRFishBar. My MPG is still crap at 11.5 mpg combine city/hwy driving. Lowest is 9.5 mpg if just driving around the local neighborhood and 12 mpg if driving on the local freeway.

If I drive long distance, I can problaby get around 13.5-14mpg. The real test will come in a couple of weeks when I make my DFW to Denver trip.

Dunno why some 5.9 w/3.92 axles and AWD reports insane MPG of around 17-19 mpg. Would love to know why they get it and we only get almost half that.

My conclusion, overall, only the map sensor replacement made a BIG change in my truck's behavior. Everything else did not make any difference.

 

Because they are wrong or overly trusting in their overhead computer. My 2000 5.9L 3.92 gets 12MPG weekly on mixed daily driving. I can drive it easy or hard, summer or winter and it's 12MPG. I am full time 4x4 too... no 2 wheel option.

Over the interstate travels, I average 15.5. That's it. 9 years, same results since day 1.

IndyDurango

 

At least I don't feel alone out there now! I have a coworker at work that has a 1st gen durango 5.9 with awd and he's pulling around 18-20 mpg on hwy. He don't use the overhead to calculate either. Just trusty fill up tank and record # of miles driven and work the math. But he lives in Maryland.. Maybe its the air out there! haha

The experiment was fun while it lasted. The money I spent on sensors weren't terribly bad and at least I did not have to blow alot of money and got no benefit from it.

At least I can say it is proven from everyone in the durango and dakota sections that had replaced the map sensor, improvement in power and respond there was definitely there!

Now I have a spare OEM O2 sensor that I will keep as a back should my replacement one ever goes out.

 

Hiya everyone, I just make my trip to Denver so I am still trying to get used to the high altitude here. MPG was impressive. I averaged 15.5 mpg coming to Denver from Dallas. The overhead showed around 13, but I did the math and trusted this the 15.5 result instead. I was expecting much worse than this because I will be slowly climbing up all the way there. When I was in Pueblo and Colorado Springs where the Durango worked the hardest, the clutch fan stayed engaged and I had to deal with the extra fan noise doing 75 MPH. But just after Colorado Springs, the clutch disengaged and temperature dropped from 195 back to my 180 setting. But the fan clutch did not drain anymore mpg at least!

My speed average around 65-70 on my first tank due to night driving. But break of dawn, I pushed to 70-75 to stay within speed limit while in Texas and New Mexico. But once in Colorado with their 75 mph limit, I ran 75-80.

I will be leaving Denver back to Dallas on Sunday. I will keep you posted. This time, I will be driving downhill all the way, maybe I will get lucky and break the 17 mpg barrier.

 

I just came back from a trip to Maryland in mine pulling a 5500 lb car trailer combo with the D fully loaded with luggage an 4 people, ran out of O/D the whole way getting 12-14 MPG at 60-70 MPH. Yesterday we went 385 miles and burned 1 3/4 tanks, not too bad IMO. The truck with its 5.9L/ 3.55 gears never missed a beat.

 

BEWARE OF ETHANOL!! It cuts gas mileage by up to 4 mpg. Trust the station you frequent and verify they are selling straight gasoline. I know this may be 'old news', but it's very true. I just made a 400 r/t trip. Going I was burning up the balance of gas with ethanol. Only got 14.4 mpg hwy. Coming back I filled up with straight gas. Got 17.6 mpg hwy. Did the math and it was accurate. Other than the gas, I keep the plugs clean and use a K&N air filter. It's Hyper programmed for 93 octane but burn 87. If you think burning a higher octane will give you more power and better mileage - think again. It's only for high compression engines that need a slower burn and knock on the lower octane. 87 octane has a lower flash point and will burn much better in our engines. I programed for 93 to advance the timing and give additional power and torque. Works

 

I said it before and I'll say it again:

I think it's the plugs Kensai.

 

And I'll say it again, don't knock it til you try it! IR plugs are fine for the 5.2/5.9 family engines!


I finally got back from my trip. Average around 16 mpg. Best I ever got since I own this truck. Funny thing is that my clutch fan locked up on my only in the Colorado area. Not sure if these damn clutches are altitude sensitive but it sux big time hearing that fan roaring for a good part of of the 10 miles. I thought I was gonna suck up what good mpg I had going but luckily it did not. Coming back home, it locked up on me for a good 20 miles in New Mexico area. I pretty much made up my mind and going to ditch that crap *** clutch fan and replace it with a Efan.

 

LOL

Maybe about time then Kensai. It should give ya a good 1-2 mpg's.