Taking to shop for MPG issues; what to check?

[samsd]

Short story about gas mileage and power, my brother had a 71 Mustang Mach1, 351 Cleveland, 4 speed, car was a dog then the crank snapped, something was binding. Put in a new motor and what a difference that made. He let me have the car while on his honeymoon in 1975. I was a stupid 18 year old but had a blast with his car, spit out a few Camaros along the way.
My Ranger does not get the gas milage othes report but on a recent trip to Atlanta I was getting 25+ running about 75, best mpg ever for me. Good weather, no wind, Rangers do not like wind. Maybe at 53000 miles it finnaly getting broke in?

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[Jacob]

Have them check the spark plugs. My MPG dropped to 16 and checked the plugs to find the infamous rust from the lack of an engine cover. Replaced the plugs with NGK and boom back up to 20/21 (‘19 4x4 w/one size bigger tires and light bar on bed)

 

[JasonTremor]

You noted new tires I believe. How many miles are on the truck? Which tires did you get installed specifically? Size and brand/model? How many miles did your prior tires last?

A few things I would check have been mentioned already. Fuel trims short and long term. Long term trims could indicate a variety of mechanical issues or even an abnormally high content of ethanol in your fuel supply. Given it is California, I would be curious just how much ethanol your stations are serving up. I've read some posts in other forums where some of the stations in California were serving up e15 back when the pump max was stated at e10. The new max is supposed to be e15, but could vary. It isn't the end of the world if this is the case, but your mpg will be lower than it could be with less ethanol content. I would anticipate e15 causing between 5 and 10 % reduction in mpg.

Just be prepared mentally for the Ford service center to send you on your way with a note that no codes are found and test drive indicates vehicle appears to be functioning normally.

 

[pbethel]

Send an oil sample to Blackstone or other and find out for sure if oil is excessively fuel contaminated.
Makes it harder for dealer to brush off your concerns.

 

[jsphlynch]

Send an oil sample to Blackstone or other and find out for sure if oil is excessively fuel contaminated.
Makes it harder for dealer to brush off your concerns.

As documented in various threads on the matter, dealers are plenty willing to brush off Blackstone reports.

 

[jblc]

Have you added running boards, mud flaps, skid plates, removed the front air dam?

No running board, no skid plates (I removed them), I purchased a front air dam instead and put that on my fx vehicle instead because the mpg was so bad, and yes I have mud flaps (but have had them since the start from factory)

Any forescan mods?
Any intake mods, air filter change, spark plugs?

none of these mods.
forescan: no mods beyond cosmetic, ie no beeping, light modes, etc. No changes to how the vehicle runs.

Add a brake controller, modified suspension, brake changes?

yes brake controller, but that will do nothing regarding MPG
Stock brakes
suspension: Bilstein 5100 front/rear, but not right away. Set to stock height (ie no leveling)

They have no idea what mileage you were getting from the start and will look at any changes you've made as the cause. They aren't going to run extensive diagnostics free of charge.

True...

If you have forescan, I'm pretty sure you can check the items airline tech mentioned.

Yep, I have a lifetime license. I thought forescan couldn't do deeper diagnostics though, only code checks, but will have to look again.

My MPG dropped to 16 and checked the plugs to find the infamous rust from the lack of an engine cover.

Good idea to check. I purchased an engine cover right away, so hopefully plugs are okay.
Do you have pics of what your rust looked like? Just to compare, if I check mine myself -- although I heard the 4th plug can be a challenge to get out and check.

 

[airline tech]

No running board, no skid plates (I removed them), I purchased a front air dam instead and put that on my fx vehicle instead because the mpg was so bad, and yes I have mud flaps (but have had them since the start from factory)


none of these mods.
forescan: no mods beyond cosmetic, ie no beeping, light modes, etc. No changes to how the vehicle runs.


yes brake controller, but that will do nothing regarding MPG
Stock brakes
suspension: Bilstein 5100 front/rear, but not right away. Set to stock height (ie no leveling)


True...


Yep, I have a lifetime license. I thought forescan couldn't do deeper diagnostics though, only code checks, but will have to look again.


Good idea to check. I purchased an engine cover right away, so hopefully plugs are okay.
Do you have pics of what your rust looked like? Just to compare, if I check mine myself -- although I heard the 4th plug can be a challenge to get out and check.

You can view about 98 % of the available PIDs with Forscan including Fuel Trims- it’s the bi-directional control that is highly limited- example: manually command EGR valve open or Fuel Pump to run, Climate Control: Door Actuators Open/Closed
These are functions that Ford blocks on most non dealer scan software

 

[jblc]

#4 spark plug (closest to windshield) looks great overall, as expected for 8k miles. The gap is right at 0.030 using wire gauge tool.
Not sure it's worth checking the other 3, as this one looks so nice...

Edit: added 3rd pic based on comments later on.

Note: Ford's manual doesn't recommend anti-seize, so i'm reinstalling it dry, contrary to what i've done with other vehicles....

 

[yamahaSHO]

#4 spark plug (closest to windshield) looks great overall, as expected for 8k miles. The gap is right at 0.030 using wire gauge tool.
Not sure it's worth checking the other 3, as this one looks so nice...

Note: Ford's manual doesn't recommend anti-seize, so i'm reinstalling it dry, contrary to what i've done with other vehicles....

I sent you a PM.

 

[canyonslicker]

A few observations here, using premium fuel and mpg goes down. It can be a combination of things. Spark plugs and/or ignition timing first, A/F mixture is rich (injectors). You can check for dragging brake by immediately feeling the rim temperature after a good drive, if one seems slightly higher then there’s the culprit.
My experience is I had low mpg until hit over 16k miles.. otherwise I have nothing further to add. It’s all been said..

 

[canyonslicker]

#4 spark plug (closest to windshield) looks great overall, as expected for 8k miles. The gap is right at 0.030 using wire gauge tool.
Not sure it's worth checking the other 3, as this one looks so nice...

Note: Ford's manual doesn't recommend anti-seize, so i'm reinstalling it dry, contrary to what i've done with other vehicles....

That looks rich to me..

 

[canyonslicker]

If it was me, I would change plugs and air filter as a start. Maybe an oil analysis is in order.

 

[jblc]

You can check for dragging brake by immediately feeling the rim temperature after a good drive, if one seems slightly higher then there’s the culprit.

Ah, this is a neat approach. Just to make sure, you mean the wheel rim, right? Will brake heat transfer well through to an aluminium rim?

That looks rich to me..

Interesting; what makes you say that?
BTW I looked at this link here and here after reading your comment, and then realized that I didn't include an angle looking inwards (my bad), so here's that:

If it was me, I would change plugs and air filter as a start.

Thanks. air filter is still great condition, but I have a spare on hand and I could change it. Same with plugs: I have another set, but seems like swapping without fixing anything else would just cause the new plugs to be ineffective as well... unless you're saying that the plug above doesn't look good?

 

[canyonslicker]

Ah, this is a neat approach. Just to make sure, you mean the wheel rim, right? Will brake heat transfer well through to an aluminium rim?


Interesting; what makes you say that?
BTW I looked at this link here and here after reading your comment, and then realized that I didn't include an angle looking inwards (my bad), so here's that:

Thanks. air filter is still great condition, but I have a spare on hand and I could change it. Same with plugs: I have another set, but seems like swapping without fixing anything else would just cause the new plugs to be ineffective as well... unless you're saying that the plug above doesn't look good?

Ok that plug looks normal at that angle. Yes heat will transfer to the rim, short of a thermal camera to see rotor temperature this is the next best. Feel close to the lugs almost immediately after your trip.

 

[canyonslicker]

JB,
You’ve got to try something that should manifest itself as cause and effect. If no effect then go further. Don’t expect instantaneous results.. What I’ve learned is design of experiments doesn’t mean singular changes but many/or a few at a time. When the results shift then you’re on to something with the latest change. Just don’t mire yourself into speculation and rhetoric… do something and test it out. Sometimes small changes will result in great results.

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