Gas Mileage

[2000black&gold]

Hey Guys,

I wanted to see if anyone else noticed what I noticed. I recently took a road trip (3,300 miles in all). I got pretty good gas mileage, especially at the beginning of the trip (22 mpg). We took all back highways - no interstates, so that helped some (btw, I have a 2000 Explorer with the 5.0 and it's AWD). Towards the end of the trip, it seemed as if the gas mileage dropped off a bit. The other day was the first time I have driven it in two and a half weeks. It seemed like the same thing - like it was getting worse than normal gas mileage. There's been times in the past when I've noticed it doing it. Towards the end of the road trip, I added some Marvel Mystery Oil (a fuel injector cleaner), and it seemed to have no effect. I also added some Marvel before the road trip. Like I said, gas mileage at the beginning of the road trip was great. Back in April I installed a K&N Air Filter, so I don't believe that area's the problem.

Anyone have any suggestions or think they might know what it is causing this change? Like I said, there's been times in the past where it does this. I probably get 50 miles less per tank. Could it be the gas I bought (although I added $15 here and $10 here the other day - different gas stations, different gas). Thanks in advance!

 

[jayhawkexplorer]

How are you measuring mileage? A lot of things can affect gas mileage. The amount of wind on the highway when you're driving, windows open/down, tire pressure, weight in the vehicle, A/C on or off. Use the search function, you'll find a ton of information on this topic, as most of us have had mileage issues at one time or another.

 

[Blee1099]

Your complaining about getting less than 22 MPG? Hell I'm content if I get 16 MPG. The average Explorer gets between 15-21 MPG. Yours is fine.

 

[gavin]

Your complaining about getting less than 22 MPG? Hell I'm content if I get 16 MPG. The average Explorer gets between 15-21 MPG. Yours is fine.

I agree... I've only broken 16mpg once in the 3 yrs I've owned my Explorer.

 

[drstein]

Your complaining about getting less than 22 MPG? Hell I'm content if I get 16 MPG. The average Explorer gets between 15-21 MPG. Yours is fine.

I'm getting about 15-16 right now (1994 XLT) - who's getting 21 and what magic dust did they put in the engine??

Or is that just highway? Mine doesn't seem to change that much.. highway, city, mixture of hte two, I can barely get to 240 miles before I'm on E (I zero the trip meter every time I fill up all the way)

 

[aldive]

Take a look at http://www.explorerforum.com/forums/showthread.php?t=44372&highlight=quest

 

[2000black&gold]

Thanks for your replys. It was rare that I got 22 mpg, and yes, it was all highway... all back highways where the speed limit was about 55 mph. But still, when those rare instances do occur and I get bad gas mileage, I am probably getting about 14 to 15 mpg on the highway. Like I said, everything that I know of is in great shape on my Explorer... the oil is changed religously at 3,000 miles, the K&N air filter only has about 3,000 miles on it. So I was just wondering if anyone knew what would cause the gas mileage to suddenly drop off like that, and then return to "regular" a tank or two (or three) later. My guess would be the gas, the only problem is that it will be different gas stations with different brands of gas and it does the same thing. Just wondering if anyone had any guesses.

 

[aldive]

A sudden drop in gas mileage can be caused by oxygen sensors. Have you monitored their function?

 

[2000black&gold]

Aldive.... thanks for your reply. No I haven't monitored their function. Perhaps I'm wrong, but I thought if the oxygen sensors messed up that the check engine light would come on. If I'm wrong, please let me know. BTW, how do you monitor them, or what type of place could I take it to have them checked out?

 

[aldive]

The O2 sensors can, and often do, function at a level below what they are supposed to function. In this condition, one can experience poor mileage.

 

[2000black&gold]

ok thanks aldive... how would one determine if that is indeed the problem?

 

[aldive]

ok thanks aldive... how would one determine if that is indeed the problem?

Hook up an OBD II scanner and monitor the O2 sensor functions.

 

[2000black&gold]

Ok thanks, I appreciate your help.

 

[spindlecone]

Hook up an OBD II scanner and monitor the O2 sensor functions.

Was not aware that the functions could be monitored, with an OBD11 scanner you can ck if they are viable or defunct, but as to how they are functioning? maybe so

 

[Blee1099]

Was not aware that the functions could be monitored, with an OBD11 scanner you can ck if they are viable or defunct, but as to how they are functioning? maybe so

Only certain OBDII scanners can read realtime data. There are quite a few of them out there on the market that don't have that ability.

 

[spindlecone]

Only certain OBDII scanners can read realtime data. There are quite a few of them out there on the market that don't have that ability.

Thx Blee
What data can one get from an O2 sensor, my scanner will tell me if I am in open loop or closed, was never aware that O2 sensors put out any realtime data, just curious

 

[peterbrown77]

I had a 4wd 92 5-speed that consistently returned 21mpg on my commute, and 22.5 or so if only highway. 2 months ago I bought a 2000 Eddie Bauer V6 (had 244,700 on the 92) and the best I can coax out of it so far is 16.5 (measured by fillup, not the trip computer). I am babying the thing too, driving FAR less agressively than I drove the 92. I've seen as bad as 15.2, and I'm not a happy camper. Aldive had some good advice, I've installed a K&N, and cleaned the MAF. Dumped a couple of cans of injector cleaner in too. I have some Bosch platinums to put in this weekend, and I'll check the wires then. Next is the O2 sensors, but I wonder how many mpg I will have to pick up to pay for them - what should I expect to pay for the up and downstream sensors anyway?

Regards

 

[aldive]

Use Motorcraft double platinum plugs instead.

How do you know you need O2 sensors?

 

[gavin]

I had a 4wd 92 5-speed that consistently returned 21mpg on my commute, and 22.5 or so if only highway. 2 months ago I bought a 2000 Eddie Bauer V6 (had 244,700 on the 92) and the best I can coax out of it so far is 16.5 (measured by fillup, not the trip computer). I am babying the thing too, driving FAR less agressively than I drove the 92. I've seen as bad as 15.2, and I'm not a happy camper. Aldive had some good advice, I've installed a K&N, and cleaned the MAF. Dumped a couple of cans of injector cleaner in too. I have some Bosch platinums to put in this weekend, and I'll check the wires then. Next is the O2 sensors, but I wonder how many mpg I will have to pick up to pay for them - what should I expect to pay for the up and downstream sensors anyway?

Regards

replacing the O2 sensors isn't necessary, and won't do any good, unless the current ones are no good. And generally, if they're no good, the truck will run either very lean or very rich, and *generally* (not always) throw the CEL.
and expect to pay right around $50'ish for each O2.

 

[aldive]

Put an OBD II scanner on th it and test the O2 sensord function before you spend money on new ones,

Good luck ......