I have a 2005 Edge extended cab 2wd with all the pollution equipment. I am getting approximately 20 mpg and want to know what kind of improvement in fuel efficiency I can expect.
Thanks

 

Welcome to the forum

You are "up north" so will be using winter fuel which has less energy than summer fuel so lower MPG would be expected this time of year.
Also the Colder the air the lower the MPG, laws of physics

You should only have PCV, EGR system and Cat Converters, neither effect MPG, or performance, if they are working OK
That's always been the Myth of Anti-Pollution add-ons to engines, lol, the only one that actually did effect MPG and performance was the "air pump" that was powered by a fan belt, like running with AC on all the time, those were in the 70's

What engine do you have?

I assume 4cyl 2.3l, since people with V6s would be HAPPY with 20MPG, in a pickup truck, lol

How many miles on the upstream O2 sensor?
They start to wear out after 100k miles, and will cause Richer running as they do


PCV(positive crankcase ventilation) pulls Blow-By(vaporized oil) out of the crankcase and burns it in the engine
EGR cools the cylinders under load so lowers NOX emissions, also prevents pinging/knocking so a more aggressive spark timing can be used
Cats just keep the exhaust hot enough to burn off more emissions, they also use a chemical reaction to clean it up

The Myth comes from these systems being broken, so lowering MPG or performance, so if removed things improve, but they would improve more if system was repaired :)

 

my 01 3.0 5 speed 2wd edge is getting 20-21 mixed mpg on winter fuel...

 

I have a 3.0 l automatic rwd with 167000 miles.

 

At over 150k miles I would change both upstream O2 sensor unless you know they have already been changed

As Dngr Rngr said 20MPG would be normal, even high, for 3.0l with Automatic on winter fuel

Also look on the drivers door label, get the stock tire size and compare it to your current tire size
The Diameter of the stock tire is what was used to calibrate the speedometer/odometer
If it came with 27" tires and you now have 28" then odometer will be off, it will read lower than actual miles traveled, not much, but can throw off MPG calculations 1 or 2 MPG with a 1" or 2" change

Google: tire size calculator

If you need diameters

 

i still need to change my O2's with 208K miles on it....springtime project haha. Got any tips on replacing them? Get engine up to operating temp and try to get em off hot? Get em hot spray with kroil? Remove cold? Ive replaced a few but usually done cold or warm but not hot and a normal wrench spun em out.. I did have 3 that absolutely refused to budge. I got the special socket even and it was spreading apart...

 

I've been getting 20 mpg for quite a few years. No the sensors were not changed. There must be something I can do to improve consumption. What about headers and dual exhaust?

 

I would try removing O2s cold, if it doesn't work then heat up exhaust, shut off engine then spray O2s with cold air that can break loose rusted threads
You don't need an air compressor, you can buy small cans of compressed air



Change the O2s after 150k for sure, O2s use a chemical to detect Oxygen in the exhaust, that chemical gets used up, so they wear out, manufacturer specs 100k miles, I have found 150k is OK, IF(big if) there was no engine issues that would cause coolant or too much oil to get into exhaust, that can shorten O2 sensors life.

Headers/exhaust manifolds are setup to provide lower pressure at the exhaust ports in ONE of 3 RPM Ranges, these are called scavenging exhausts, been used since the 60's/70's
Low band
Mid band
High band

Rangers come with Mid band scavenging exhaust manifolds

Low band is the most popular change, more low end power for "get up and go", but you lose the mid band power, might help MPG if you are a lead foot when starting off, you have more low end power so get up to speed faster so less time with "foot to the floor", although it wouldn't be much of a change

Single or dual exhaust, at one time the dual exhaust conversion might have helped MPG, now it's just a sales tool for exhaust sellers
Properly designed single exhaust system won't cause any "back pressure" at any RPM, Ranger has this

Dual exhaust looks better and can sound better, but you have to double up on the Cats and Muffler so an expensive conversion

In higher horse power engines the dual exhaust can improve performance by using "H" or "X" pipes between them, so technically back to a Single exhaust system, lol


One conversion that helps mpg AND Power is using an electric fan on the radiator
The mechanical fan uses horse power and fuel the whole time the engine is running, is it much, no, is it 0 no again, lol, so it does lower MPG and power
The fan is there to pull air thru the radiator at lower speeds and when stopped, at higher speeds the vehicles travel pushes more air thru rad than any fan can pull, so its not being used but still drawing power from the engine.

An electric fan(e-fan) is temp controlled, so comes on when needed and goes off when not needed, yes it DOES draw electrical power from alternator when its on, which does draw extra power from the engine.
When driving at speed, best MPG, the fan will be off for better power and better MPG, when driving slow or stopped, 0 or very low MPG, lol, the fan will be on as needed

So removing the mechanical fan and adding an e-fan is a win-win conversion, and not too expensive