My 2001 Ford Expedition is guzzling gas like no other. I have had a tune up, new tires and oil change. But I am still getting about 12 miles per gallon is there anything that I can do to get more MPG?

These are ideas only as there are many things that could improve gas mileage.
When was the last time you had a tune up? (Spark plugs check for bad sensors . When was the Air filter changed..
do you always check the air pressure in the tires. Low tires can bring your mileage down five miles per gallon or more.
Do you drive with fast starts and stops.
Do you run short trips? Short trips does not let the engine warm up to the right traveling temperature. I live in town and I get about 15 miles per gallon in town but if I drive 20 miles or more I get 24 or more with my Buick.
You will get less mileage if you drive in real cold weather.

Check that you have the proper air pressure in your tires. Change the air filter. If you're constantly hauling a lot of people or stuff, the extra weight will lower fuel economy.
Next go with a tune-up- new sparkplugs and wires.
You may also want to look for a small fuel leak. This could be particularly dangerous if you have one. If it is a fuel leak, don't drive the vehicle until it's repaired.

your oil change has nothing to do with your check engine light. probably needs spark plugs and a coil or 2

no it would be due to a few things,,,,,,,,,,high miles ,,,,not changeing oil on time,,pitston ring wear from both .

The tune-up is a Fred Flintstone term,
meaning you got spark plugs or payed
for them and got nothing

You need new spark plugs
You need 2 new front O2 Sensors, if you
have 100,000 miles on them
You need the MAF Sensor Cleaned
A Clean Air filter
Correct fuel pressure
A properly working TPS Sensor
(throttle position sensor)
And other items.

See if you have all that done, and get back
I will evaluate your issues.

Do you have check lights on the dash
If so give us the codees

on normal that trk should be around 6-7 gallons used per one hundred miles drove. i based that at 15 mpg. now that is also based on a V8 engine. now 1 gallon of gas is 3.78541178 liters which totals 12 galons of gas to 45.42494136 liters. This would mean that it took 12 gallons of gas to travel 100 miles which totals 8.3333333333 mpg. not as good as i would have thought. 8 miles per gallon (mpg) hell that engine must be a big block 460. If it is that big cubic inch i could understand but any other motor should do better mpg than 8.3. so i agree that is not normal, tune up, or look for fuel leak in the fuel supply or( feed ) line. From the tank to the motor. This must be a canadian truck yes? well hope for the best or trade that guzzler in for a new breed. stay warm!

Tune Time.
1)new spark plugs properly gapped.
2)new air filter (check every 35000 miles)
3)new fuel filter (every 35000 miles)
4)1 bottle of STP fuel treatment (red bottle) 4x a year.
5) oil and filter change (castrol or another good quality oil every 3-4000 miles.
6)proper air pressure in tires (check every 2 months
7) service transmission every 40000 miles or less.

New oil and filter
8) new plug wires every 80000 miles.

You could fill the tires with Nitrogen but it will cost about $15 a tire. You will gain 1.5 - 2 miles more a gallon. Big trucks were made for pulling and hualing only. If your looking at gas mileage then you need a focus.

Check the driveshafts/ Universal joints in the driveline.

My Answer:

Poor gas mileage can be a result of many many things.

First of all you need to find out what is the factory normal gas mileage for your model year Jeep SUV. It should have said on your window sticker if you bought it brand new. If you are a 2nd or 3rd owner then a Jeep dealer would have info. Google search will tell you as well, and only takes a couple minutes to find.

I did a quick Google search and for a 2003 Jeep Grand Cherokee with a (4.7L V8 engine) the average mileage is roughly 14 mpg.

Not sure what engine you have as to options, etc?

How you drive will greatly change that number up or down depending on a number of driving and driver variables.

A few being -

Driving habits?

Tire pressures?

Engine tuned up?

Lube & oil/filter changes (every 5,000-7,500 miles? Air filter changes (every 10,000-15,000 miles)? Read your auto manual for exact recommended intervals.

How many people in the SUV on average?

Are you towing anything?

Type gas you are burning - BRAND? (See injectors below)

Area you are driving in (hills and valleys verses flat out,
etc)

Jeeps in general don't have a good track record for great mileage, and rough engine idling is always a clue that your fuel injectors are dirty. Typical on all Jeeps with port fuel injection systems! On Jeeps with dirty fuel injectors your mileage will go way down accordingly. If your not putting at least a 12 oz bottle of say Walmart brand Super Tech Fuel Injector Cleaner (~ $1 each) in your gas tank religiously every logged 1000 miles, or every 2 tank fill ups, then you are just inviting dirty fuel injectors and POOR fuel economy!

My 1993 Ford XPLR with a 4L V-6 engine (and ~ 160,000 flawless driven miles) gets roughly 22 miles per gallon on the highway with cruise control on, and about 17 around town on average. I religiously put a 12 oz bottle of the above injector cleaner in my gas tank every 1000 miles!! Of course I do all my own tune-ups, general repairs, and suspension maintenance (shocks, O2 sensors, trans oil changes, lube & oil/filter changes, code reading and clearing, etc) myself and it shows! I don't trust repair shops except for say Tires and Balancing at SEARS.

Hope that helps ease your mind about gas mileage as it relates to your Jeep there.

Frank