2002 4.2 with 150K miles - What MPG should I expect?
#1
11-29-2014, 02:03 AM
Join Date: Apr 2003
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2002 4.2 with 150K miles - What MPG should I expect?
2002
F150
4.2 V6
Auto
2WD
Regular cab, short bed
For the first 140,000 miles of this truck, I could easily manage 20 MPG on the highway. By the time the fuel gauge needle hit the halfway mark, I'd be right around 210-215 miles on the trip meter and could easily squeeze 400 miles out of a tank. Now, I'm lucky to hit 190 on the trip meter by the time the needle is at the halfway mark and I'm at low fuel light around 370.
Once the mileage got bad, I started double checking the MPG after each fillup by doing the calculations in a logbook. On average, for the past year I've gotten about 16MPG highway.
The truck has been maintained meticulously otherwise. No codes, idle is as smooth as when it was new, no rust, no damage. No extra weight added to the truck, still running 255/70 factory tires.
Am I a fool to think I should still be getting 20MPG highway?
F150
4.2 V6
Auto
2WD
Regular cab, short bed
For the first 140,000 miles of this truck, I could easily manage 20 MPG on the highway. By the time the fuel gauge needle hit the halfway mark, I'd be right around 210-215 miles on the trip meter and could easily squeeze 400 miles out of a tank. Now, I'm lucky to hit 190 on the trip meter by the time the needle is at the halfway mark and I'm at low fuel light around 370.
Once the mileage got bad, I started double checking the MPG after each fillup by doing the calculations in a logbook. On average, for the past year I've gotten about 16MPG highway.
The truck has been maintained meticulously otherwise. No codes, idle is as smooth as when it was new, no rust, no damage. No extra weight added to the truck, still running 255/70 factory tires.
Am I a fool to think I should still be getting 20MPG highway?
#2
11-29-2014, 08:17 AM
2002
F150
4.2 V6
Auto
2WD
Regular cab, short bed
For the first 140,000 miles of this truck, I could easily manage 20 MPG on the highway. By the time the fuel gauge needle hit the halfway mark, I'd be right around 210-215 miles on the trip meter and could easily squeeze 400 miles out of a tank. Now, I'm lucky to hit 190 on the trip meter by the time the needle is at the halfway mark and I'm at low fuel light around 370.
Once the mileage got bad, I started double checking the MPG after each fillup by doing the calculations in a logbook. On average, for the past year I've gotten about 16MPG highway.
The truck has been maintained meticulously otherwise. No codes, idle is as smooth as when it was new, no rust, no damage. No extra weight added to the truck, still running 255/70 factory tires.
Am I a fool to think I should still be getting 20MPG highway?
F150
4.2 V6
Auto
2WD
Regular cab, short bed
For the first 140,000 miles of this truck, I could easily manage 20 MPG on the highway. By the time the fuel gauge needle hit the halfway mark, I'd be right around 210-215 miles on the trip meter and could easily squeeze 400 miles out of a tank. Now, I'm lucky to hit 190 on the trip meter by the time the needle is at the halfway mark and I'm at low fuel light around 370.
Once the mileage got bad, I started double checking the MPG after each fillup by doing the calculations in a logbook. On average, for the past year I've gotten about 16MPG highway.
The truck has been maintained meticulously otherwise. No codes, idle is as smooth as when it was new, no rust, no damage. No extra weight added to the truck, still running 255/70 factory tires.
Am I a fool to think I should still be getting 20MPG highway?
back, old-timer! ( Join date April 2003 !!!! )Please describe yer definition of 'meticulous maintenance'. It's more than just regular oil and filter changes - much more.
How many miles are on the (front) O2's ?
How many miles are on the plugs?
Have you ever changed the PCV?
Have you ever cleaned the MAF, TB, EGR ports?
Have you ever had a Motorvac service done?
Have you had the cats checked for incipient plugging?
Parking brakes / disc brakes dragging?
Onset of other parasitic drag - e.g. the fan clutch.
On so on .... note that the above will not set a CEL or store codes, typically...
---On that note above, have you ever had the presence of pending codes checked? They may not necessarily set a CEL. E.g. random / intermittent low-grade misfires - over time they can contribute to clogging cats and more. Difficult to detect via SOTP or butt-dyno.
That's a 20% drop given yer figures - some, but not all of it can be attributable to overall aging & wear ( not factoring in seasonal fuel formulations ).
Not implying anything here, as I'm sure you already know these things given yer tenure - just throwing out some ideas, aight?
good luck
MGD
Last edited by MGDfan; 11-29-2014 at 08:49 AM.
#3
11-29-2014, 02:12 PM
Join Date: Apr 2003
Posts: 2
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Hi & back, old-timer! ( Join date April 2003 !!!! )
Please describe yer definition of 'meticulous maintenance'. It's more than just regular oil and filter changes - much more.
How many miles are on the (front) O2's ?
How many miles are on the plugs?
Have you ever changed the PCV?
Have you ever cleaned the MAF, TB, EGR ports?
Have you ever had a Motorvac service done?
Have you had the cats checked for incipient plugging?
Parking brakes / disc brakes dragging?
Onset of other parasitic drag - e.g. the fan clutch.
On so on .... note that the above will not set a CEL or store codes, typically...
---On that note above, have you ever had the presence of pending codes checked? They may not necessarily set a CEL. E.g. random / intermittent low-grade misfires - over time they can contribute to clogging cats and more. Difficult to detect via SOTP or butt-dyno.
That's a 20% drop given yer figures - some, but not all of it can be attributable to overall aging & wear ( not factoring in seasonal fuel formulations ).
Not implying anything here, as I'm sure you already know these things given yer tenure - just throwing out some ideas, aight?
good luck
MGD
back, old-timer! ( Join date April 2003 !!!! )Please describe yer definition of 'meticulous maintenance'. It's more than just regular oil and filter changes - much more.
How many miles are on the (front) O2's ?
How many miles are on the plugs?
Have you ever changed the PCV?
Have you ever cleaned the MAF, TB, EGR ports?
Have you ever had a Motorvac service done?
Have you had the cats checked for incipient plugging?
Parking brakes / disc brakes dragging?
Onset of other parasitic drag - e.g. the fan clutch.
On so on .... note that the above will not set a CEL or store codes, typically...
---On that note above, have you ever had the presence of pending codes checked? They may not necessarily set a CEL. E.g. random / intermittent low-grade misfires - over time they can contribute to clogging cats and more. Difficult to detect via SOTP or butt-dyno.
That's a 20% drop given yer figures - some, but not all of it can be attributable to overall aging & wear ( not factoring in seasonal fuel formulations ).
Not implying anything here, as I'm sure you already know these things given yer tenure - just throwing out some ideas, aight?
good luck
MGD
Once the MPG issue appeared, I went all out and replaced anything I could that didn't involve pulling the engine or tranny.
Both upstream and downstream O2 sensors were replaced less than 10K miles ago.
Spark plugs were replaced less than 10K ago
PCV also replaced less than 10K ago
I've cleaned the MAF, TB, and EGR ports when I had the upper plenum off to replace the butterfly actuator grommets (forgot the actual term)
Not sure what a motorvac procedure is?
Took the truck to a muffler shop who checked the cats for plugging.. some light cracks but nothing that would impede flow
Brakes don't seem to be dragging
Not sure about the fan clutch..do these trucks even have those? As far as I know, the fan on my F150 runs all the time
I have a Scangauge as well as a OBD code reader and no codes come up. I've logged the fuel trims while driving and short term + long term trims on both banks rarely exceed 10%.
You may be right that this is just age.. which I am willing to accept, but I'm just concerned that the drop in MPG is due to some part that may be failing soon leaving me stranded on the road.
#4
11-29-2014, 05:16 PM
Motorvac is the same thing as a BG job - a chemical intake tract and combustion chamber cleaning done with a machine. I have it done at every spark plug change.
I would recommend putting Techron in the gas to clean the injectors.
You definitely have a clutch fan, which should not be running all the time.
My 03 with 175k gets the same mileage it got at 55k when I bought it, unless I pick up some poor energy content high ethanol fuel.
Have you ever had the transmission fluid serviced with an exchange machine? Ever had the differential lube changed?
I would recommend putting Techron in the gas to clean the injectors.
You definitely have a clutch fan, which should not be running all the time.
My 03 with 175k gets the same mileage it got at 55k when I bought it, unless I pick up some poor energy content high ethanol fuel.
Have you ever had the transmission fluid serviced with an exchange machine? Ever had the differential lube changed?
#5
11-30-2014, 10:16 AM
Might take a look at the tires. When I changed brands of tires from the factory originals my gas mileage dropped 27%. The tires I had bought had a max rating of 35lbs where the factory tires were 41lbs. Made that much difference in the rolling resistance. Check the tires for the max air pressure and air 'em up. Unless Ford made the tires and obviously they didn't, the stamp on the door panel is meaningless info. Ask any of the older Exploder owners. Works great for the factory originals but not the replacement tires. In a lot of cases, a cheap tire will effect gas mileage negatively.
#6
12-02-2014, 10:15 AM
