HELP Gas Consumption increased to double!

[Surfo]

Hello! I know jeep Liberty is not very efficient engine but his is ridiculous!

I would like to know if anyone has any idea of the increase in fuel consumption.

I have a 2006 Liberty 4x4 when I was bought it gave me around 18 mpg with 30,000 miles on it, NOW with 80,000 i just get around 9 or 10 mpg

I been servicing with good NGK spark plugs in addition to its synthetic oil, etc ... Ive haven´t done any major service, since it runs great with lot´s of power !

What will be the list of things to replace? maybe the injectors?

Thanks

 

[LibertyTC]

A tune up is best as in spark plugs champion or NGK copper core every 25 k miles for starters, air filter, clean IAC, throttle body, and good fuel injector cleaner like Chevron Techon Concentrate.
The rear axle lube should be clean do this every 25k miles see owners manual for Lube and Limited slip friction modifier if you have a Trac-Lok rear end.
Change transfer case & front diff fluids as well..see owners manual.
Increase air pressure in tires 3-4 psi over recommended cold tire pressure.
Remove any unnecessary cargo/weight etc.
Drive it easier..pedal to the floor = Bye Bye to gas mileage.
Get it on the highway with the injector cleaner more often if you are city driving too much & blow the dirt/carbon out!
Use good fuel..I run 94 octane in mine..non ethanol thank you.

 

[Surfo]

Thanks for your reply, I've done all that only for the front dif oil change, do you thing it could be a problem with the O2 sensor? no check engine light are on?

 

[LibertyTC]

If anything you could have the jeep read by a high end scanner like a dealer star scan or an Actron/ Snap on if you wanted to see live performance readings/any pending codes etc.
The Jeep emissions sensors will generally trip a trouble code if there is a problem.
I would not fire the C02 parts cannon yet, unless I was sure it needs sensors.
The other thing you may want to do is have the dealer perform an emission service.
They will inject pro chemicals into the fuel rail, and for $130 aprox.? ..it may very well help in the fuel mileage department

 

[wheeee32]

Change any fluids that you haven't done yet, such as a coolant flush. A quality injector cleaning service will help. The fuel tank added ones don't really do much. Since we're on fuel, you could look at changing the fuel filter also. It isn't hard to get at either.

 

[Surfo]

Thank you all I go and get a full scan to look for error codes!

 

[ivantate]

I would jack up each corner and make sure the brakes arent binding on. That mpg problem is alot more than coolant or axle fluids.

 

[Leeann]

Since we're on fuel, you could look at changing the fuel filter also. It isn't hard to get at either.

He has an '06. The fuel filter is a non-serviceable part of the fuel pump.

 

[Birdman330]

The winter months are setting in, also keep in mind the winter blends will be coming out that also means loss of fuel economy. I've already noticed that now the seasons are changing despite filling to the top, I'm losing 20 miles total out of my tank since the start of these last two tanks. Nothing different in my driving habits, engine runs the same, sounds the same.

 

[Hedsic]

Jeeze. That's worse MPG than I had with 4" of lift and larger mud terrain tires. I think I got around 12mpg average with stock gearing. I have a heavy foot.

 

[Surfo]

I have no lift kit I run 245/75/R16 I live in Puerto Vallarta Mexico and is very hot here, I will go after a full scan to look for error codes! Thanks I let you guys know.

 

[tommudd]

Larger tires without re-gearing , there is part of the issue

 

[CactusJacked]

I have a 2006 Liberty 4x4 when I was bought it gave me around 18 mpg with 30,000 miles on it, NOW with 80,000 i just get around 9 or 10 mpg

A 9 mpg loss is a lot.
Did it have the 245 tires at 30k miles?
If you up-sized the tires between then and now, did you notice any drop in mpg right after that point?
Or, is this poor mileage a more recent development that's not tied to previous change in tire size?

 

[MarkJ]

I agree on the brake check. Especially the e-brakes.
Mark

 

[wheeee32]

Larger tires without re-gearing , there is part of the issue

Yeppers.

 

[Surfo]

Well Ive started with the scan, and there was only one error: P0304 Misfire Detected in Cylinder 4, Ive changed spark plugs error is gone, do you think that could be causing extra gas consumption?