I have never been able to fully correctly calculate my MPG, as I haven't tried, but I am wondering how accurate the two are? Why I ask is because I don't know if i'm just burning through gas like crazy for some reason, or if the DTE thing is just fubar.

(plenum? But have very little oil consumption just under 1/2 Quart in about 2,100 miles on a truck with 232,000 miles and no loss of power, ran a diagnostic with a bluetooth ODBII reader and also didnt get any bad codes, or abnormal readings from O2 sensors.)

I put $25 in today and it was at the line just below the half full mark, I mainly use the truck for in town driving and very short trips, and I am not too heavy on the pedal, but today after putting $25 in the gas tank read 131 DTE, after driving about 8 miles to the next town and back for a total of about 16 miles and maybe a total of about 3 miles of normal in town driving, the DTE calc is reading at like 95 saying I drove about 36 miles, when I know I only went about 20.

I let it sit for awhile since I know gas swooshes about lol and it never went up, with that reading it's like I am getting like 6-8MPG in town, horrible lol.

 

What is your in town driving like with multiple stops and acceleration 6-8 I would say is the norm. Also the DTE goes by your average fuel economy and gallons used they aren't know to be very accurate mine is off my 2-3 Mpgs.

 

I'm assuming the Ram's trip computer works the same as my Durango's does here. I know in my Durango it takes longer for the gas gauge to go from F to 1/2 than it does from 1/2 to E, so that could be why your DTE is going down more quickly.

As for how accurate the MPG is, sometimes it is sometimes it isn't. I've been keeping track of how accurate the computer's MPG is for a while, so here's the numbers from that:

 

Yeah, there is A LOT of stop, go and accelerate in town with the truck, there is more of that frequently than there is just like a 10 minute drive.

 

Welp, I think I have found my problem, my CEL came on again for P0138, it came on ages ago and dissapeared and hasn't came around for over 7 months, so I am assuming my bad downstream o2 Sensor could be causing this what seems like a major loss of gas mileage, next check I am going to replace them both, how hard are they to replace on a 2000 Dodge RAM 1500 2WD Laramie SLT 5.2L V8?

 

The downstream o2 just checks if your cat is working. The front is what influences a/f ratio and contribute to bad gas mileage.

 

Crawl under your truck and look.

 

It's very easy. The upstream is the key sensor like Ham Bone said. It helps to have an O2 sensor socket. The initial pull to break it free is the only "tough" issue. Just follow the sensor cable to its connector. Be sure you feel the new sensor snap in.

 

I sprayed my o2s with PB blaster for about 3 days, unhooked the wires, then used an open ended wrench. came out easy.

 

Ah, well regardless next check I am gonna go ahead and replace both o2 sensors to be on the safe size, I think they are both stock sensors with 232,000+ miles.