Fuel Mileage in ye old toilet

[1997SCEBFEX]

aside from weather, there might be something else as the culprit.
MAF
Fuel filter/air cleaner; former on frame rail (I believe & for my model anyway.)
intake sludge build up
injectors
....
sure others will chime in.

Have you done any other maintenance?

 

[JExpedition07]

Still guarantee it’s weather mine is averaging 14 MPG in this cold and normally averages 17 MPG, it starts climbing back up as soon as we get a warm day.

 

[ExplorerTom]

What would you expect the culprit to be for my 3-4mpg loss after intake installed?

A K&N intake? Assuming based on your signature.

2 things come to mind:
1. You drive it harder because the intake sounds cool
2. The filter is oiled too much and that oil is now covering your MAF downstream.

 

[J Ski]

aside from weather, there might be something else as the culprit.
MAF
Fuel filter/air cleaner; former on frame rail (I believe & for my model anyway.)
intake sludge build up
injectors
....
sure others will chime in.

Have you done any other maintenance?

Truck has 20K miles on it and gets oil
Changed every 3500 miles. If any of this stuff listed is the culprit Ford is going to have some explaining to do. I don’t have a MAF, they are now MAP sensors (3 I believe) which I may end up cleaning with some CRC

 

[J Ski]

A K&N intake? Assuming based on your signature.

2 things come to mind:
1. You drive it harder because the intake sounds cool
2. The filter is oiled too much and that oil is now covering your MAF downstream.

It’s oiled from the factory and you can barely tell it’s even got oil on it

 

[plumcolr]

Check for a dragging brake caliper. Easiest way is with a cheap gun type remote thermometer; drive ten or more miles and immediately check the front rotors and the rear rotors. If there is a difference left-to-right (forget front-to-back) the hotter rotor is dragging. I'd say check with finger but if it is really dragging you could easily end up with a blister.

 

[plumcolr]

And it's not winter fuel so much as even injected it's run slightly richer until the engine is at operating temp. Cold start also means fluids (oil, trans fluid, gear oil) are thicker, so the same engine performance requires more fuel.

 

[JExpedition07]

Truck has 20K miles on it and gets oil
Changed every 3500 miles. If any of this stuff listed is the culprit Ford is going to have some explaining to do. I don’t have a MAF, they are now MAP sensors (3 I believe) which I may end up cleaning with some CRC

You have a MAF sensor, every modern engine does. That is the mass airflow Sensor that measures air being taken into the intake into the engine for combustion. The MAP (Manifold Absolute Pressure) sensor measures vacuum not incoming air.

 

[rjdelp7]

In western NY it has not been warmer than 19, in two weeks. It is near 0 at night. Mine is down at least 2+ miles per gallon. I do not do any extended warming up or idling and mostly short trips. The extreme cold, kills gas mileage.

 

[J Ski]

You have a MAF sensor, every modern engine does. That is the mass airflow Sensor that measures air being taken into the intake into the engine for combustion. The MAP (Manifold Absolute Pressure) sensor measures vacuum not incoming air.

You are incorrect. Ecoboost 3.5s DO NOT have MAFs, they are MAPs and there are three of them. Our motors are speed density based and do not use a MAF sensor. Airflow is calculated based off intake manifold pressures along with temps.