02 explorer 4.0l 12mpg

[justanother1]

Looking for ideas on what to check to improve gas mileage on wife's 02 explorer 4.0L 130,000 miles. currently is getting 12mpg. Everything is stock with the exception of a 3" BTF lift and after market wheels (stock size Discover AT3 tires). Intake gaskets, valve cover gaskets, plugs (motorcraft), & wires were done at 124,699. Occasionally we get a sulfur smell from the exhaust but have gotten that since we got this in May of 2012. Recently replaced thermostat housing because it was leaking. We have no check engine light. Runs good, no loss of power but doesn't quite get to operating temp in her 20 minute drive to work. Clutch fan seems to be working ok. What are your thoughts?

 

[Number4]

It should get to operating temperature within 5-7 minutes of driving.

When I drive my wife's '05 4.0, I get 17mpg. When my wife drives it, she gets 12-13. She gasses it until she has to brake, even when she can see the red light. Not sure how your wife drives.

I've always been told that a sulfur smell from the exhaust means un-burnt fuel. This will eventually destroy your cats and would certainly hurt your gas mileage.

 

[Number4]

Speaking of which.

 

[justanother1]

Unfortunately with the brutal cold temps (lower than normal) we are having here in PA, it takes longer than 5-7 minutes to get to operating temp.

My wife said she had been easy on the gas for a couple tanks without any real improvement.

The original plugs were worn to .090 gap (I think these may have been the original plugs from new). Not sure how much of this would have put unburnt fuel into the converters.

I may put a piece of cardboard in front of the radiator to see if that will help getting to operating temp quicker and have her drive our f150 for a couple days.

 

[justanother1]

I did put a piece of cardboard in from of the radiator which did help get to operating temp quicker. I replaced the thermostat and removed the cardboard. Might have taken 7-10 minutes (on my trip to work) to get to operating temp.

I have also adjusted the idle to run about 550 - 600rpm with the iac valve unplugged. Not sure this is going to make a difference on mpg.

We just filled the gas tank last night. We'll check mileage to see if there is any improvement next time we fill it up.

 

[shadowless127]

Its the brutal cold temps. My gas mileage has gone to crap lately, and my brother's gf (who lives in PA) mentioned last night how she feels like shes been using more gas lately.

 

[Berky]

My 04 4.0 runs great and only get 12mpg as well. New plugs, wires, etc