Tips for improving MPG? Please Help

[scottswierenga]

My 93 X is suffering from worsening gas milage. When I first got it, about 2 yrs ago, we could get about 260-280 miles from the 16+ gallon tank (15.6mpg) and ever since it's slowwly getting worse . Now I am lucky to be running on fumes to get to 210 which works out to about 12.6 mpg; at best . It doesn't seem like much at first but it equates to about 4 days less of commuting and getting kids to/from school between fill-ups. Driving to and from work is about 14 miles round trip & school drives for the kids is about 5 minutes round trip. One suspision I have is the frequent short trips is a factor to killing my MPG as the engine isn't fully reaching full operating temp.

I have tried:
keeping tires at about 44psi (manufacturer recommended)
bottles of injector cleaner
replaced the air filter to a higher flowing K&N.

None of these seem to have even been able to maintain MPG over the long run.
The explorer has 124,000 miles on it, a new tranny earlier this year:thumbdwn: , and new tires that are 31x10.5x15 versus the stock tires that were two inches less in diameter at the time of replacement. I know the larger tires affect the registered MPH but the change in MPG didn't happen immediatly after the switch. I also don't have a Lead Foot but accelerate modestly.

Do you think I should try a spark plug change out? (I have no clue how old the current ones are)
Any comments or suggestions would be much appreciated.

 

[aldive]

Take a look at the thread in my signature.

Goofd luck ....

 

[scottswierenga]

I see that you have switched to synthetic oils, I wanted to switch to synthetics, something like maybe Quaker State High Milage but I was informed that if I wanted to have made the crossover to "fake" oil then it should have been done long ago, milage-wise. Something about smaller oil paritcles finding every possible leak location as the engine seals degrade over time.

I also read that after you lowered it your MPG got better, i.e. less drag. I am starting to think that on mine by having gotten slightly taller tires and the eventual addition of my three off-road lights to the roof rack that I have been increasing the disturbance of airflow over and around my truck and in turn increasing the drag and decreasing my own milage from that.

OK, but what about the fact that even though these additions were done over 18 months ago my milage continues to decrease? The last tank I filled burned 16.6 gallons on 171 miles (10.3mpg)...and all I did was buy a new battery.

It must have been the Hydralically mounted harmonic dampener for the battery acid's wire harness that did it this time

 

[Maniak]

When you changed the tires, did you regear your speedo?

If not your speedo/odo is off about 7%..

Also, when you put on a taller tire (w/out regearing)normally your around down mileage will drop because you need more torque to get moving.

Synthetic fluids in the diff and xfer case did seem to help on our x.

Also, most places have a winter blend of fuel.. which normally gets you wose mileage.. Plus you drive a larger percentage of the time in open loop than you do in summer..

Last thing.. check your mileage by keeping track of how far you go and how many gallons of fuel you use.. not by what the fuel gauge says..


~Mark

 

[gsx220]

mine is at about 10mpg to i have 31's and 3.55 gears only getting like 180 or so to like 17 gallons

 

[scaperrotta06]

try the fuel filter and plugs and wires maybe even the diffs...also try cleaning the maf etc
when i changed my fuel filter and the diff to synthetic i got 1-2 mpg better

 

[scottswierenga]

I did not regear it after the tire change out, I am not even sure of which gears it has in it. I have always calculated mpg based off of the trip-meter divided by the number of gallons at filling. I have been thinking of a fuel filter change and yes, I have cleaned the MAF...gently with a toothbrush and some gas.

 

[marragtop]

Start with the normal maintenance stuff... plugs, wires, fuel filter, and PCV valve. I think you said you already did the air filter. Best way to do plugs is thru the wheel well.

 

[uh60james]

Intersting that you mentioned the smaller oil particles of a synthetic. I never real though about it. I have a small leak from the pan that got worst after switching to synthetic, time to go back to dino oil.

 

[marragtop]

Do some research before you switch back from syn to regular. I've heard you're not supposed to do that. Although, I don't have any first hand experience with it.

 

[aldive]

Do some research before you switch back from syn to regular. I've heard you're not supposed to do that. Although, I don't have any first hand experience with it.

I see no reason to ever switch back, however there is no reason why you can't.