Just wondering what your Durango's are getting for gas mileage?? I have a 99 with the 5.2 and 120K, and my trip computer is telling me that my average is under 10 MPG!! A very far cry from the 15 city and 19 hwy! There's no check engine light on, so it's not one of the sensors. I just replaced the plenum gasket figuring I might get better mileage just because there was no more oil going in the combustion chamber?any help would be appreciated!!
EXTREMELY crappy gas mileage!!
Martinistr8up1
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Just wondering what your Durango's are getting for gas mileage?? I have a 99 with the 5.2 and 120K, and my trip computer is telling me that my average is under 10 MPG!! A very far cry from the 15 city and 19 hwy! There's no check engine light on, so it's not one of the sensors. I just replaced the plenum gasket figuring I might get better mileage just because there was no more oil going in the combustion chamber?any help would be appreciated!!
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MPG tips
Your O2 sensors have 120K mi and need replacement if originals. They're the potentiometer link to the PCM and injectors. Clean your TB. I still think you might have a PCM issue though? how's your stall issue? Ensure your tires are correctly inflated, keep your foot out of it, and check your air filter. Also fresh plugs and distributor cap/rotor can help ensure complete combustion chamber burn. Eliminate ethanol fuels. Summer blends are here? surprise! Less mpg.
HTH
Bill
Your O2 sensors have 120K mi and need replacement if originals. They're the potentiometer link to the PCM and injectors. Clean your TB. I still think you might have a PCM issue though? how's your stall issue? Ensure your tires are correctly inflated, keep your foot out of it, and check your air filter. Also fresh plugs and distributor cap/rotor can help ensure complete combustion chamber burn. Eliminate ethanol fuels. Summer blends are here? surprise! Less mpg.
HTH
Bill
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my trip computer is showing 13.6 right now with 1700miles since I reset it. normally its close to 15. but I pulled a trailer 2weekends ago. I did pull 19 driving I-81/I-135 to south Dakota earlier this month though.
eliminate ethenol fuels? I run the unleaded plus which around me is 89 or 90 octane with 10% ethonal in it?my D runs better on it than regular 87.
eliminate ethenol fuels? I run the unleaded plus which around me is 89 or 90 octane with 10% ethonal in it?my D runs better on it than regular 87.
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Never an always?
Hey, if it works for you go for it. I get consistently 3mpg less with it. IMHO "ethanol" is best served chilled where I come from. Costs less too.
I don't mix my flex fuel with my D. They sorta frown on that, and we all want to be responsible users, er consumers. :cheesy:
Bill
Hey, if it works for you go for it. I get consistently 3mpg less with it. IMHO "ethanol" is best served chilled where I come from. Costs less too.
I don't mix my flex fuel with my D. They sorta frown on that, and we all want to be responsible users, er consumers. :cheesy:
Bill
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Are you refering to the overhead trip computer? It has been pointed out to me that those can be pretty inaccurate, and indeed mine seems to be off by a couple mpg or so.Martinistr8up1 said:
My overhead computer used to average appx 14mpg but these days more like 12mpg? so something seems to be up. I'm checking it manually against my ODO to see how far off. I have the 4.7L.
SOmeone mentioned ethanol in the gas. Is there anything we can do to avoid it? I mean do the 87, 89 & 91 octane gas differ in their levels of ethanol?
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Re: MPG tips
Bill how do you know if O2 sensors need replacing? And is it easy to do? MY D is 8 yrs old but only has 53,000 miles (sits a lot).Volphin said:
ML_Clayton: If your mileage hasn't gone to pot don't fret the Oxygen sensor issue.
Another mileage factor could be a leaky injector/s.
You can't check for either one without a sniffer in the tail pipe and/or a tool that reads your computers inputs.
Another mileage factor could be a leaky injector/s.
You can't check for either one without a sniffer in the tail pipe and/or a tool that reads your computers inputs.
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Added variables, different results.RebelX said:
IF you could get ethanol in 87, your mileage would suffer over gas at the same 87. You have changed 90 for 87 in your illustration. 90 gas would be better than 87 gas too.
Higher octane, slower burn, more fuel used. Ethanol needs a slow burn, hence the higher octane. E85 is 100 octane!
IndyD
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I'm sure mine sucks. 174,000+ on factory 02s. The codes I got last winter haven't came back so I haven't changed them/it (I only bought the precat one.) BUY, MPG seems the same since day 1? FT4x4 5.9L = 12ish MPG.
IndyD
IndyD
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It has been about a week since I replaced the crankshaft sensor and it seems to be running great. It has been pretty hot here(CT) and I have been running the A/C just to make sure it gets nice and hot under the hood. My throttle body looks clean(what little there's of it), there isn't a check engine light on so I'm thinking the O2 sensors are fine. There isn't any misfiring either. The last thing I have to replace is the fuel pump assembly because the check valve is bad(fuel pressure drops rapidly when I shut the car off)?any other ideas??
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MPG
Most O2s are rated for 80-90K mi. FYI
Re ethanol, the feds say the pump must be labeled to identify if it's in the gas. Usually a yellow decal, most common is 10% blend.
Martin, how's your fan clutch, any roaring at all? Your 318 should do better than my 360. Are you calculating with pen & paper of by console?
Bill
Most O2s are rated for 80-90K mi. FYI
Re ethanol, the feds say the pump must be labeled to identify if it's in the gas. Usually a yellow decal, most common is 10% blend.
Martin, how's your fan clutch, any roaring at all? Your 318 should do better than my 360. Are you calculating with pen & paper of by console?
Bill
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122 Posts
I replaced my crankshaft sensor 3-4 months ago as well? the engine light came on and it ran really rough, but after having it replaced everything runs great.Martinistr8up1 said:
It seems my decrease in mileage (from 14 down to 12) has occured over the last 6 months, I don't know if that's concidence or not. :?: Maybe someone else here would have an idea about this.
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True
Checked out means they didn't pop a MIL.
The voltage sweep is what you need to measure in open and closed loop operation. Over time the heat, the etheleneglycol residue and carbon by products will weaken it's sniffing ability. And they're designed to fail rich. Lean would be disasterous.
Some fail due to contamination fairly early in life as witha blown head gasket leaking coolant into the combustion chamber. That'll wink em right out.
Some lose effectiveness over time (normal).
Bill
Checked out means they didn't pop a MIL.
The voltage sweep is what you need to measure in open and closed loop operation. Over time the heat, the etheleneglycol residue and carbon by products will weaken it's sniffing ability. And they're designed to fail rich. Lean would be disasterous.
Some fail due to contamination fairly early in life as witha blown head gasket leaking coolant into the combustion chamber. That'll wink em right out.
Some lose effectiveness over time (normal).
Bill
My overhead always says around 11-12mpg. I don't know if that accurate. I never checked with odometer. I have 32" tires. Does that affect the overhead display? also the tires affect the odometer right? I know my speedometer is off very slightly, I'm just wondering how I figure our how many actual miles I'm going on a tank? I'm thinking the overhead is a lilttle off. I replaced the o2 sensors, plenum gasket, cleaned throttle body and air filter, put on gibson catback exhaust, new catalitic converter, put royal purple in differentials, changed tranny fluid, changed oil to full synthetic and washed and waxed and overhead still says same as it always has since I got it! not sure, guess its just thirsty!
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