4.2l Mpg ?
Senior User
Joined: Oct 2003
Posts: 432
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From: Bishopville, MD
I would like to have the mileage I used to get on my 04 Heritage Scab 3.55 Auto 4x2. My F250 CC 4x2 Auto with 3.73 rear is getting 13.5-14.5 mixed very slow keeping it under 2000rpm driving I only have 1300 miles on the truck hope it improves with breakin time.
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
Have you guys (tula and Tstorms) had your PCM reflashed?
I have read a few acounts of re-flashing having and impact on performance and mpg.
I'm not going to touch mine. If it ain't broke, don't fix it!
With the new electronic controled throttle body (no more throttle cable) the computer manages the throttle body based on pedal position and various other engine parameters.
If I was getting as crappy mpg as you guys, I'd be lloking for a re-flash. You got nothing to lose really.
I have read a few acounts of re-flashing having and impact on performance and mpg.
I'm not going to touch mine. If it ain't broke, don't fix it!
With the new electronic controled throttle body (no more throttle cable) the computer manages the throttle body based on pedal position and various other engine parameters.
If I was getting as crappy mpg as you guys, I'd be lloking for a re-flash. You got nothing to lose really.
Junior User
Joined: Nov 2005
Posts: 87
Likes: 0
I have a brand new truck, got it in November, and it has a build date of November. It runs great, no complaints except the mpg, my dad drives a "hemi" 4 by four quad cab, and gets better mpg than I do..........and he does not let me forget!!! lol
Senior User
Joined: Nov 2004
Posts: 324
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Isn't 2100-2300 rpm a little high? I don't like running my 4.2 at that speed. Why is the manual trans. geared higher than the automatic?
Okay, if my 4.2 5 speed runs at 2100-2300 rpm, then why am I getting 20 city and 21-23 mpg highway? What is making my 4.2 achieve that mpg????? And its a 4x4!!!! I always thought 2wd trucks got better mileage than 4x4s since 2wd trucks don't have to deal with a heavy front axle and transfer case.
Thanks!
Okay, if my 4.2 5 speed runs at 2100-2300 rpm, then why am I getting 20 city and 21-23 mpg highway? What is making my 4.2 achieve that mpg????? And its a 4x4!!!! I always thought 2wd trucks got better mileage than 4x4s since 2wd trucks don't have to deal with a heavy front axle and transfer case.
Thanks!
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
2100-2300 rpm is not high at all. You can run it there forever and it is perfectly content.
I don't think the manual and auto are geared differently for a specifc reason unique to the 4.2 application.
The 5 speed is a Mazda design and is used in a variety of applications.
The auto is a Ford design, again used in various applications.
The difference in final drive (OD) is not that much. I believe the manual is .9:1 and the auto is .8:1
As for your truck's mpg? I dunno.
I don't think the manual and auto are geared differently for a specifc reason unique to the 4.2 application.
The 5 speed is a Mazda design and is used in a variety of applications.
The auto is a Ford design, again used in various applications.
The difference in final drive (OD) is not that much. I believe the manual is .9:1 and the auto is .8:1
As for your truck's mpg? I dunno.
Junior User
Joined: Nov 2005
Posts: 87
Likes: 0
Filled up today, MPG=15.5!!!!! The best ever. I have an appointment next week to get the computer flashed. Gas was 2.89 a gallon, WOW. I do not understand, I'm sure demand is going down as people do not want/cannot pay these prices. My truck is 5-months old, now I have 3200 miles, I drive the truck to work and home and do my business and pleasures either way. On a day off I take the truck out and get everything done. My wife wants to turn in the Freestar for a VW TDI----50mph, so between the gas sucking truck and the TDI we have the best of both worlds. No, I have never had a foreign car, but 50mpg sure looks good for the everyday car!!!
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
Hmm...
I'm still averaging about 18 mpg combined.
Got 21.8mpg one time on the interstate (and that was pulling my little utility trailer with my motorcycle in it.)
Yes, rising gas prices is a pain in the wallet.
I'm still averaging about 18 mpg combined.
Got 21.8mpg one time on the interstate (and that was pulling my little utility trailer with my motorcycle in it.)
Yes, rising gas prices is a pain in the wallet.
Posting Guru
Joined: Jun 2005
Posts: 1,065
Likes: 0
From: Oshkosh Wisconsin
Hey guys i just finished reading this whole thread (wheeoo)
Just thought about my situation:
I have a 99 std cab flareside 4.6L manual with 89,000-ish miles. I'm only averaging around 15-16 city and highway isn't much better. I bought this truck, as i'm sure most of you have done, hopeing for better milage... My buddies dad has the same truck (shrt bed not flareside) and he had 156,000 on it and he gets 20 like you do Brian... I'm not sure what the heck is going on here. I tried changeing the general stuff plugs wires air filter oil and what not...
I read the re-flashed computers.. what does this do is it somethign I should check out?
Thanks,
Brian
Just thought about my situation:
I have a 99 std cab flareside 4.6L manual with 89,000-ish miles. I'm only averaging around 15-16 city and highway isn't much better. I bought this truck, as i'm sure most of you have done, hopeing for better milage... My buddies dad has the same truck (shrt bed not flareside) and he had 156,000 on it and he gets 20 like you do Brian... I'm not sure what the heck is going on here. I tried changeing the general stuff plugs wires air filter oil and what not...
I read the re-flashed computers.. what does this do is it somethign I should check out?
Thanks,
Brian
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Junior User
Joined: Nov 2005
Posts: 87
Likes: 0
I finally put in a K&N air filter and did I get a surprise at the gas station!!!! 18-mpg combined!! A three mpg increase. I do not think the total increase was from the filter, but I believe the filter improved the air intake and forced the computer to make some changes.
New User
Joined: Mar 2006
Posts: 16
Likes: 0
I have the 3-door extended cab(1997, 4.2, aod). I can get 16 on good days, when my wife drives it, 12-13 tops. She drives with 1 pedal on the floor at all times
If I had not just got it and owe the bank, I'd get a good old 302 4 barrel with a C6 and put in. couldn't do any worse.
If I had not just got it and owe the bank, I'd get a good old 302 4 barrel with a C6 and put in. couldn't do any worse.
Postmaster
Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
a) reflashing the computer will verify/update the programing in the truck's "brain". This involves fuel mapping curves (for the fuel injection), timing curves (for ignition timing), shift points (if you have auto transmission), etc.
You might want to have it done if you think it is worth spending your money on. No hard and fast answer to that question UNLESS there are known issues with a specific model.
b) tula, that is good new and interesting too! I wonder why? Well, even if we never know exactly why, if it makes that big of a difference, then it is a good thing!
c) I don't think there is any noticeable difference across all model years. The variation seem wide, regardless of model year.
I continue to get the same as always.
My all time high is 21.8 mpg (see recent post) and I just got my all time low (as far as I know) this past week.
16.9 mpg. Lots of city driving, running the A/C, stop and go traffic, blah blah blah. The conditions where you expect lower mpg. Aside form that, I hang around 18 mpg combined.
You might want to have it done if you think it is worth spending your money on. No hard and fast answer to that question UNLESS there are known issues with a specific model.
b) tula, that is good new and interesting too! I wonder why? Well, even if we never know exactly why, if it makes that big of a difference, then it is a good thing!
c) I don't think there is any noticeable difference across all model years. The variation seem wide, regardless of model year.
I continue to get the same as always.
My all time high is 21.8 mpg (see recent post) and I just got my all time low (as far as I know) this past week.
16.9 mpg. Lots of city driving, running the A/C, stop and go traffic, blah blah blah. The conditions where you expect lower mpg. Aside form that, I hang around 18 mpg combined.
New User
Joined: May 2006
Posts: 2
Likes: 0
New 2006 4.2 5 speed Mileage
I have just under 1000 miles, My 1st hiway trip was before 500 miles. I got 19.5 mpg on that trip travelling 65-75 with the flow of traffic. I am doing 2100 to 2150 RPM at 70mph. I have a Reg Cab, Short Bed with the 255/65/17 tires.
I love it, I should have bought an F150 in 93 when I bought My Ranger.
I love it, I should have bought an F150 in 93 when I bought My Ranger.
New User
Joined: May 2006
Posts: 7
Likes: 0
Hello everybody! I'm new to the site. My mpg varies quite a bit also. I bought my 02 F-150 Supercab used in 04. With the original 235/70/16 tires the mpg averaged about 17 with a high of 20 on trip to VA. Bought some new tires 2 weeks ago (265/70/16) and the mpg has dropped to about 15
New User
Joined: Mar 2006
Posts: 16
Likes: 0
That would explain my miserable mileage, if the same therom can be applied working in reverse. I do not know the mileage with smaller tires (yet
). I get between 14 & 16 with 265/75-16. They would be equal to 33x12.50-16. They make it look good, more like 4x4, but they are way too much tire for 2wd v-6.
I plan to go back to closer to factory size, no bigger than 245/75-16.
). I get between 14 & 16 with 265/75-16. They would be equal to 33x12.50-16. They make it look good, more like 4x4, but they are way too much tire for 2wd v-6. I plan to go back to closer to factory size, no bigger than 245/75-16.
Last edited by 4doorkick; Jun 2, 2006 at 07:38 AM. Reason: forgot to mention looks