Help,Low MPG!

[jrseykid686]

I have an 02 Eddie Bauer V8... my MPG is dropping and i dont know why. I have about 85K on it. I was getting upper 14mpg average and now i have dropped off to 12 at best. I do very little highway driving, and really dont drive it hard... at all. I am a firefighter so it does get driven hard a few times a week for just a few short miles. Any suggestions on what i can do to help boost this?? i am reading people getting up near 18MPG... that would be a dream... please help!

 

[Charlie]

I would recommend a full tune up, being at 85k things are starting to get worn. Check tire pressures, alignment, ect ect. Cleaning engine components like MAF might be helpful. Check air filter, and you might want to run some fuel system cleaner thru it. That one helped for me a lot.

 

[Ranger379]

plugs and wires, fuel filter, like he said: check and clean the MAF and IAC, maybe PCV valve

 

[jrseykid686]

What does the PCV do?? also what about fuel filter... when is a good time to replace that. Somebody said something about a fuel delivery filter? or something like that.... what is that? Tires are new, with a 4 wheel alignment, K&N filter. I am planning on a tune up before it gets cold, i live in MI and its already getting cold. How hard is a wire/plug on the 4.6. I havnt taken off the plastic cover and checked it out yet. Is it an easy replace? or one of the replacements you have to roll the engine for

 

[aldive]

Have you scanned for O2 sensor function?

 

[Ranger379]

What does the PCV do?? also what about fuel filter... when is a good time to replace that. Somebody said something about a fuel delivery filter? or something like that.... what is that? Tires are new, with a 4 wheel alignment, K&N filter. I am planning on a tune up before it gets cold, i live in MI and its already getting cold. How hard is a wire/plug on the 4.6. I havnt taken off the plastic cover and checked it out yet. Is it an easy replace? or one of the replacements you have to roll the engine for

fuel filter is pretty easy to replace, just buy the little tool to take the lines off. the one you replace is the in-line filter, there is one in the tank also, you wont reaplce that. on the second gens its on the frame rail, id look there.

never done plugs/wires on a third gen, helps if you have small hands most of the time lol, try not to break the wire taking it off the plug, but if you reaplce wires the same time you replace plugs, then it dont matter. i usually use needle nose pliers in some cases. the changing of the plugs and wires is very simple, just getting to them can tricky lol

 

[jrseykid686]

I have not scanned for O2 sensor function yet, my car has no engine light on so i havnt thought about that. I'm going to try to get the plugs/wires done today, depending on this stupid weather and if i have the time this afternoon. Still one thing i am unsure of... the PCV? what is it and when should it be replaced? Also, is it time for a fuel filter? or am i just jumping the gun on that... the car seems to run fine, just crappy mileage
Thanks

 

[ghoster]

like every has said..do a full tune up..make sure to change the coil pack also..and you should see a gain in mpg
i have a 04 Eddie but a v6..i do drive it hard at times and i'm getting 13-14 is not i get 18-21, mostly highway

 

[daprez1963]

oops

 

[daprez1963]

I have not scanned for O2 sensor function yet, my car has no engine light on so i havnt thought about that. I'm going to try to get the plugs/wires done today, depending on this stupid weather and if i have the time this afternoon. Still one thing i am unsure of... the PCV? what is it and when should it be replaced? Also, is it time for a fuel filter? or am i just jumping the gun on that... the car seems to run fine, just crappy mileage
Thanks

The Positive Crankcase Ventilation valve, or PCV valve, is a one-way valve that ensures continual evacuation of gases from inside a gasoline internal combustion engine's crankcase.

 

[jrseykid686]

where is that valve and how hard is it to replace?

 

[cjones101812]

the image i have shows it on the valve cover.

 

[joecap]

If it just started to drop it's probably the gas formula change to winter blend. That kicked in here in Michigan recently. Mine dropped about 1-1.5 mpg last week, it's been the same in all of my past cars over the years. Maybe it kicked in Oct 1?

Flip side is that the winter blend is supposed to be cheaper, personally I havent seen the reduction yet.

JC

 

[jrseykid686]

Yea, gas is still 3.09 here, its on its way down. My car was in the shop today, turnes out it was the IAC motor, car runs great now, more power, better mileage and even shifts better and sounds better

 

[E.B. Cornburner]

As the weather gets colder, your MPG will drop too. They blend the fuel differently in the wintertime to aid in cold starts, but these lighter aromatics blended into the gasoline such as butane, heptane, etc. have little heat energy and will hurt your MPG a bit.

Interestingly, as gasoline-fueled vehicles start losing MPG due to the different fuel blend, I may be experiencing a little better MPG...E85 isn't a true 85% anymore when it's colder, but somewhere around 70%. The added heat energy of a little more gasoline in the blend should in theory boost the MPG slightly.
If anything, I'll probably notice no change.