From what i've heard, these trucks can get into the 27-30 range. Its a 5 speed. I don't run the A/C or heater nearly at all. Most of my driving is on the freeway around 60 MPH. I always shift around 2500 RPMs and even in the 4k Range MPG does not fluctuate. No check engine light or any OBD codes

 

How are you getting miles traveled and gallons used?

i.e. if odometer is being used have you checked it or speedometer?

There are only two ways for gasoline to be lost, it leaks out, or it is burned in the engine
If its leaking you should smell it, but not always when weather is cold

If you are burning it then spark plugs will show that, pull them and have a look at the tips for the darker color of Rich running

There is a 3rd way.....................neighborhood kid with a siphon hose, lol, hey it CAN happen



And just FYI, if you have a 2001 with a 2.3l, its not a Lima engine, so wrong sub-forum, its a Duratec DOHC 2.3l
A 2001 Ranger can have either a 2.5l SOHC Lima engine or a 2.3l DOHC Duratec, Ford change to the 2.3l DOHC in mid 2001

 

I'll check the spark plugs. I know no fuel is leaking out. Also have a locking gas cap :)
About the subforum. Figured, but checked the VIN and says it has a 2.3 SOHC not DOHC

 

Last 2.3l SOHC was in 1997 Ranger

8th digit in VIN is engine size
C = 2.5l SOHC Lima
D = 2.3l DOHC Duratec

A = 2.3l SOHC, as said, last used in 1997 Ranger

VINs for cars are different than light trucks

 

Its possible you have lazy O2 sensors. I had the same, and I didnt throw a code, but saw a noticeable improvement when I replaced them.

Some other things to check for would be vacuum leaks, there are a few suspect hoses that can do that.

Also, there is a "magical" plug on the intake that likes to blow out on the 01 DOHC, or leak. It would be on the "front" of the intake, as viewed from the front of the truck. There, behind the power steering pump, near the flange, you should see a circular plug. If you don't see it, then it fell out, and is a large air leak.

The 01-02 rangers had an "air tumble" system that effectively activated butterfly valves inside the intake to change air flow and speed, supposedly to increase efficiency and low end torque. I haven't owned my truck since new, but I never noticed a difference TBH. There are a few other "waste of time" components on the 2.3 DOHC, but for the most part, the engine itself should last the better part of forever.