As of late, I've noticed that I am getting really terrible gas mileage on my 2001 Durango. Yes, I know its a Durango..but I feel like I need to take out a 2nd mortgage just to keep it going. It has a 4.7 and I'm getting around 330kms per 90 liter tank. The truck has 185,000Kms on it and runs fine. I've changed the plugs last year but am wondering if I should switch back to the Champion Truck plugs as opposed to the regular Champions. I'm going to change the air filter, but I don't think that will make a big difference.

Could it be dirty injectors or a bad valve? No codes are showing up so..I'm kinda perplexed.

Any help or insight would be greatly appreciated.

thanks!

Mewfie

 

does it smell like its running rich? if so replace front o2 sensor(s)

if one plug seems consistently wet or fouled, clean or replace that injector.

probably not a valve. you'd be getting a misfire code.

 

I hear you! Mine is a 2000 and I'm getting about 10MPGs. I'm too tired to do the math but it's not good. I am going to try new plugs when it gets a little warmer. I too have the 4.7. Love the truck hate the mileage...

 

I used to get good mileage, but I noticed that the mileage was getting worse and worse. I'll probably buy an O2 sensor along with a Map Sensor and some new Truck Plugs. Would resetting the PCM do anything at all?

 

sorry if this is wrong, that seems to be about 8.5 MPG, that is about HALF of what you should be getting, now for my questions
1) are you running the stock tire size (bigger tires = less MPG)(is your speedometer correct)
2) is the air pressure up to proper levels in the tires (i like about 35-37 psi)
3) when was the last tune up? plugs(copper core champion gapped to .040)filter ect
4) how do you drive? hammer down every time the light goes green, or do you baby it? (the best thing for your mpgs is to keep your foot out of the gas)
5) trans fluid change, make sure it is shifting properly and the trans is NOT slipping
6) check the O2 sensors (pre cat) they control mixture and can cause rich or lean running
7) normal mileage for these trucks sits around 15-16, but the epa claims you will get 13 city and 17 highway

HTH shrps,

 

No, it does not appear to be running rich at all. I'll probably replace the O2 sensor along with other stuff...

Yup for sure, love the truck...really hate the mileage. I really want to hold onto the truck because of the 7 seat and I also have 3 kids...I don't really want to get a minivan.

 

Shrps;


1) are you running the stock tire size (bigger tires = less MPG)(is your speedometer correct)

I am running 265-75-16's..a little bigger, but have been running them for the last 2 years..only lately has the gas mileage changed.

2) is the air pressure up to proper levels in the tires (i like about 35-37 psi)

Air pressure is good, though I will check it again..its only minus 25 up here in Ontario

3) when was the last tune up? plugs(copper core champion gapped to .040)filter ect

Plugs were changed last year, not the truck plug..just regular ones..I will change these to truck plugs along with filter.

4) how do you drive? hammer down every time the light goes green, or do you baby it? (the best thing for your mpgs is to keep your foot out of the gas). I

I've been really good with the truck lately, but still getting bad mileage...haven't really hammered it in a while...at least not with the kids in the truck which is alot.

5) trans fluid change, make sure it is shifting properly and the trans is NOT slipping

Tranny is not slipping. Had all the fluids changed about 60000kms ago.

6) check the O2 sensors (pre cat) they control mixture and can cause rich or lean running

I'll do that this week....I feel its an O2 or MAP sensor causing me grief. I'm not getting any check engine lights or codes.

7) normal mileage for these trucks sits around 15-16, but the epa claims you will get 13 city and 17 highway

The only gas mileage I've known as of late is CRAPPY MPG in city and highway

Thanks for your help!

 

I've always been curious about whether I should be putting unleaded or premium in my tank. I know the premium is like 20 cents more per gallon but I thought it's supposed to burn longer and be better for the car...I've only had the car for about a month now so it's still relatively new to me but if anyone knows I'd appreciate it.

 

just put regular unleaded in it unless you have a problem with the engine pinging or similar, its just a waste of money to use anything else if it runs fine on regular gas

 

there are some incorrect bits of info running around regarding octane ratings.

The oil companies would love for you to buy super but..

Octane is a rating that indicates a fuels resistance to burning, if you have a higher compression engine that knocks or pings on regular you need to increase the rating of the fuel till knock is eliminated.

the higher octane rating means the fuel will be ignited by the spark plug at the designated time. not a hot spot in the cylinder or the heat of compression.

If however you don't knock on regular & run the higher octane fuel, you're not only wasting your money but the higher octane fuel will not burn as efficiently. costing both power & economy.

On the other side, if you run a lower grade & get any amount of knock, power curve is over. you will not produce squat for power or fuel economy any higher in the band after that.

Knock & ping being pre-detonation events & now fighting the rise of the piston on compression stroke.

Back to our originally scheduled thread.