I have a 98 f150 with 5.4. I know I bought a truck and shouldent worry about fule milage but I think it should do better than 10 mpg. I dont dont hod rod it I drive normal. Is there any sugestions to getting better fuel economy besides the obvious little things.

 

Should get at least 12-13, first things to check are air filter, fuel filter and tire pressure.

 

Tire size? Any up-grades? Type of plugs and when last changed? Mileage?

 

Check the idler and tensioner pulley for excessive drag. Maybe look into electric fans. I just changed out my 02 sensors thinking it may help but think that that is just a placebo.

Pres said just to inflate the tires - problem solved; next problem.

 

The tires are fine the air filter is clean and the fuel filter was changed when i bought it at 153000mi.I have 265 75 16, KN 77 series cold air, platnum plugs changed 10000mi ago I am now at 164500. With the electric fan is that hooked up to a temprature swich? or just wire in a switch?

 

Temperature switch so you can take off your mechanical fan without worry.

 

Please define "I Drive Normal?"

Does this mean, city, stop and go traffic?

does this mean Highway at 55 or at 85?

Are you driving a Lifted F150?

If normal means that you roll on the throttle easy, accelerate smoothly, then I would check the following out

1) is the Cat plugged up? it may need replaced
2) Pull any stored codes off of the motor, see if anything is going on.
3) Check the rear drum brakes, there may be some drag that you may not be able to perceive.

If all this checks out, start over and check everything again.

 

Its not lifted and its mostly highway at 55-60. Thank you those are some of the things I was overlooking. Now that its the weekend I will have some time to play with it.a Little off topic but what are some things you guys have done to get better mpg?

 

Alignment can also eat into your economy if its wrong, besides eating your tires. As you just got the truck, it wouldn't hurt to get your alignment checked. By the time an alignment issue shows up in your tires wear pattern, its usually too late for the tire, it will be noisy and vibrate and ride rough the rest of its life, assuming it has much tread left.

If the cat is plugged (why does everyone jump to this, the cat is a victim, just like your economy is a victim) it will eat into economy and performance, but cats are destroyed and plugged by improper tuning. Misfires, bad O2 sensors, carbon build up, internal oil leaks, etc. are the main things that cause cats to plug, and so thats really what you need to check for and correct. A plugged cat is one of the last things you check, not the first. A plugged cat will almost always be preceded by low power, especially in passing gears. If you have no trouble building power and revving the engine up, the cat really doesn't belong on your suspect list until other suspects have been eliminated.

And yes, the rear brakes can sometimes drag, especially if the parking brake cable has rusted.

 

I have plenty of power and the alingment is also good. I can let go of the wheel and it drives straight as an arrow and trust me I can spot tire wear form a mile away I went through many sets of tires on my ranger and if the cat was pluged wouldent there be a CEL???

 

If the cat was plugged there would probably be a CEL and you wouldn't be able to speed up worth crap. What RPM does the truck run at 65mph?

 

My 97 S/cab 4x4 5.4 w/3.55 gears averages 14.5 mpg combined. Are your readings correct?

 

yes my readings are correct its they been constant. it rins between 1500 and 1800 rpm at 65mph

 

From reading this post, I have gathered that o2 sensors play a part in decreased fuel mileage. what other items could be overlooked? can a MAF get out of tune? I have 01 5.4 4x4 ECSB 3.55 gears running BFG T/A 265's that are E range, air pressure correct. (These were the tires on it when I bought it 6 months ago). 2000 rpm @ 72

Reason why I am responding is that I am pretty much dead stuck at 12 mpg. .5+/- I had plugs changed when #3 shot out the cylinder. ive had to replace the intake manifold due to cracked and leaking coolant, which still does time to time when the truck is sitting off. I have noticed that I burn fuel quick if I am idling while waiting on the wife in the store for 20 min. I guess maybe 1.5G.

Ive also read that real time reading will help determine if something is sensing wrong giving too much fuel. Is there a chart available to compare numbers of what sensors are in correct range readings? Ive been wanting a real time reader for a while, this may convince the wife to let me buy one.

Its sad to read about guys getting 15-18 out of the same drivetrain, even with 3.73 gears. My daily commute is 25 miles one way. 2 miles of 35mph, then its 15 miles of 70-75 mph, then down to 45 for 4 miles, with the remaining distance being going thru the gate on base and 35mph to my shop. I have driven the truck from FL to Ga and back, and then FL to OH all driving at 78mph. I did calculate maybe 14 on those long hauls, but the daily drive I am stuck at 12. <!-- / message -->

 

get one of these UltraGauge OBDII Scan tool & Information Center mine paied for itself in te hfirst 2 months on fuel savings. Between finding and fixing error codes and changing my driving style.