Poor fuel milage need help

[welderdude74]

Hello All,
This might be a newbie question but what can I do to get better fuel milage.
I have a 92 Explorer 4dr 4x4 4.0 new auto 3.73 gears 165k miles rebuilt front end from hub to hub same on rearend.So its down to engine and fuel
It has 3" body lift (bought that way) runnig 245/75-16" tires there were free and had 500 miles on them it came with 225/75-15.I have done all the norm tune up stuff.I have a adapter I made for the mas with k&n cone filter on it. When I first got it had the tinny tires on it and then got the larger one on it,but from day one it has average 10 mpg even with the tiney tires. Its used as a dd and see 75 mile round trips 5 day a week. runnning 60-65 down hwy it run about 1800-1900 rmp so to me it not gearing/tire size. I know this 4.0 should be getting better milage but not sure where to start at.

 

[welderdude74]

come on I know some one out there has some pointers

 

[fordrocks1986]

You should check tire psi put it to like 45 and spark from your plugs and your gap in them as well better gas sometimes can help and try not to take off so fast just ease in to the gas that's all I can think of

 

[j_reagan]

under drive pulley, electric radiator fan, k and n air filter, ive heard exhaust mods such as headers, and mufflers can help but i dont know first hand.
good luck

 

[Shran]

You should check tire psi put it to like 45

That is a really stupid idea if the tires aren't designed for 45psi. I haven't seen very many light truck/passenger tires that are.

under drive pulley, electric radiator fan, k and n air filter, ive heard exhaust mods such as headers, and mufflers can help but i dont know first hand.
good luck

No.

I can tell you with 80% certainty that the K&N filter you have is at least part of the problem. The oil you use for the filter contaminates the MAF.

Other than that it is just a matter of checking all the sensors and engine management stuff to make sure it's all working. Things like coolant temp sensor, oxygen sensors, fuel pressure regulators, etc can all have an effect on mileage.

 

[Robert_1967]

You should check tire psi put it to like 45 and spark from your plugs and your gap in them as well better gas sometimes can help and try not to take off so fast just ease in to the gas that's all I can think of

I hope your not running your tires at 45 pounds, that is just plain stuiped, 35 is the maxx that a light truck tire can have, unless you have the 11-22.5 or 11-24.5 that big trucks use, then it's 105 to 110 in the steer, and 100 to 105 in the drive.

Robert

 

[welderdude74]

I can tell you with 80% certainty that the K&N filter you have is at least part of the problem. The oil you use for the filter contaminates the MAF.ok then what kind of cone filter should I run beside going back to stock?

 

[adsm08]

You should go back stock. The stock intake system is a true cold air system, those K&N cone setups, unless you invest in the insulator box, very quickly becomes a HOT AIR intake. That will kill your mileage.

 

[welderdude74]

Ok then I will go back to stock air box,got to go the JY to find one,mine was all broke up when I got it thats why I whent to the k&n. I will also try getting some new sensors and such to see if it help .I am running 245X75R16 tires @35psi.

 

[Shran]

Agreed, go back to the stock setup. Aftermarket air filter crap is worthless.

You may not NEED to get new sensors - get a shop manual and test the ones you already have before you throw parts at it.

 

[chazzone]

Agreed, go back to the stock setup. Aftermarket air filter crap is worthless.

You may not NEED to get new sensors - get a shop manual and test the ones you already have before you throw parts at it.

What he said, stumbling around in the dark, pissing away money is no way to improve your truck.

Have you checked for codes?

Is your O2 sensor ('s) connected?

Are you using the correct weight oil? (5W-30)

 

[adsm08]

I haven't seen very many light truck/passenger tires that are.

Most tires are load range C or D, which are rated to 40 PSI, a lot of 16 and 17" BFG All-Terrains are load range E which are rated to 50 or 55 and actually ride pretty bad if you don't fill them up to 50.

Causes a lot of bump steer and steering wheel rock. But yeah, for an explorer that isn't loaded to the brim, 35 is a good pressure.

 

[fordrocks1986]

That is a really stupid idea if the tires aren't designed for 45psi. I haven't seen very many light truck/passenger tires that are.



No.

I can tell you with 80% certainty that the K&N filter you have is at least part of the problem. The oil you use for the filter contaminates the MAF.

Other than that it is just a matter of checking all the sensors and engine management stuff to make sure it's all working. Things like coolant temp sensor, oxygen sensors, fuel pressure regulators, etc can all have an effect on mileage.

Most tires take 40 psi these days due to how long they last look at your tires and see whAt it say it will most likely say 44 psi max so don't just open your mouth I worked for ford for 4 years I use to set tire presher to 45 All the time and not ones died yet

 

[Robert_1967]

Most tires take 40 psi these days due to how long they last look at your tires and see whAt it say it will most likely say 44 psi max so don't just open your mouth I worked for ford for 4 years I use to set tire presher to 45 All the time and not ones died yet

the ones on my Bronco II say 35 max, the ones on my ranger say 35 max, I have never seen a tire on a light duty truck say any thing over 35 max, and I have seen alot of tires and have changed out alot of tires.


Robert

 

[Shran]

Most tires take 40 psi these days due to how long they last look at your tires and see whAt it say it will most likely say 44 psi max so don't just open your mouth I worked for ford for 4 years I use to set tire presher to 45 All the time and not ones died yet

You realize that if it says 44psi max that is the safe maximum for the TIRE, not the vehicle?

Look at the door sticker, it will tell you what your tires should be inflated to. If you are running stock wheels and stock size tires you should follow that, NOT the max pressure on the tire or they will be overinflated.

If you still don't believe me, let's just agree to disagree and not start a pissing match, OK?

the ones on my Bronco II say 35 max, the ones on my ranger say 35 max, I have never seen a tire on a light duty truck say any thing over 35 max, and I have seen alot of tires and have changed out alot of tires.

+1.