4.2L Poor MPG
Senior Member
Joined: Apr 2003
Posts: 582
Likes: 0
From: Lakewood, Southern Cali
Ive got a 7 inch lift with 315/75/16 tires, 4.56 rearend gears, SCT flip chip on 91 octane, 4.2L, reg cab, short bed, flowmaster 40 muffler and I get 14 MPG when I used to get 13 MPG completely stock. Go figure?
Junior Member
Joined: Apr 2005
Posts: 6
Likes: 0
From: Central Florida
Yep, I'm averaging about 13mpg with my '03 4.2L. Very disappointing, but there are remedies. If I can up the mpg to at least 17 in the city (which is what the dam sticker says in the first place), I'll be happy.
I've read several ideas about improving mileage. What about an after-market throttle body spacer?
I've read several ideas about improving mileage. What about an after-market throttle body spacer?
Member
Joined: Mar 2005
Posts: 12
Likes: 0
From: Las Cruces, NM
The best things I have done for my mileage on my '99 4.2 are K&N intake filter, and exhaust. I went cheap and just threw a glasspack on after the cats, and it actually sounds very mellow. I also have a tonneau cover, which made quite the difference. I purchased a Tornado, which has also helped some. Hope this helps, as I am currently pulling 16.5 in town (in southern New Mexico, running the A/C all the time), and 20 on the highway...good luck!!!
Junior Member
Joined: Oct 2003
Posts: 2
Likes: 0
I have an 03 F150 4X4 with the 6 and get bad mileage too. I am averaging about 250 in town and 300 on the road. I also have an 04 Ranger and get worse mileage in it. My dad has a 02 Chevy with a v8 and gets twice the mileage I do. At this rate I don't know if I will buy another Ford truck.
Junior Member
Joined: Apr 2005
Posts: 3
Likes: 0
From: Florida
16 mpg's constant
My 02 4.2 5 speed get 16 mpg consistently. I've kept records of every tank and mileage since I bought it. (my wife thinks I'm nuts) but it helps me for maintenance and engine probs.. Anyways, I tow a 17 ft boat most of the time and the gas mileage doesn't change. Always use cruise even in 3rd gear in town.. yes im' that lazy.. It doesn't matter.. same same same..
Junior Member
Joined: Jul 2013
Posts: 1
Likes: 0
Is anyone else having poor millage with the 4.2, purchased truck 1 year ago its a 98' F150 reg cab 2wd ,XL auto and has 76k on it
I owned a 94 150 w/302 v8 before this (ext cab) auto , and I got 16-18 mpg .
The 4.2 average is 15 mpg , the highest Ive seen is 17 ,and it does not have the power of the 302 (course I knew that when I bought it )
I have the same routes and travel time so it should be as good or better u would think .
Been thinking of trading it off for a 4.6 F150
Any body got any input ?? :bows
I owned a 94 150 w/302 v8 before this (ext cab) auto , and I got 16-18 mpg .
The 4.2 average is 15 mpg , the highest Ive seen is 17 ,and it does not have the power of the 302 (course I knew that when I bought it )
I have the same routes and travel time so it should be as good or better u would think .
Been thinking of trading it off for a 4.6 F150
Any body got any input ?? :bows