Fuel Economy Update for February — Holding Steady After 30,000 Miles - 2015 Ford F-150 Long-Term Road Test

2015 Ford F-150: Fuel Economy Update for February — Holding Steady After 30,000 Miles

by Dan Edmunds, Director of Vehicle Testing on March 7, 2016

2015 Ford F-150

Like a late season batting average, it takes a lot to make a long-term test vehicle's average fuel economy budge when it's in its final months with us. But there was reason to think our 2015 Ford F-150 might be different, and that reason was this: 10,498 miles with ten quarts of oil in the pan instead of the specified six quarts.

Conventional wisdom suggested our truck's legendary poor fuel economy simply had to be the result of the crankshaft churning and stirring all of that extra oil. "It all makes sense now. Chalk it up to windage losses," they said.

Nearly 10,000 miles have passed since I changed the oil and restored things to normal. I can now parse the data into approximate thirds: The first 11,700 miles with the correct six quarts of oil, the next 10,498 miles with 10 quarts of oil, and the most recent 9,500 miles with the required six quarts of oil.

I'm sorry to burst your balloon, but that middle third, the one with all of that extra oil, did not represent a period of depressed fuel economy. And MPG did not rebound after I corrected the problem.

First third: 15.9 mpg
Middle third: 17.7 mpg
Latest third: 17.4 mpg

Did you see what just happened there? The over-lubricated middle third actually had the BEST fuel economy. That doesn't make any sense.

So I removed any tanks that were labeled "towing" and got this:

First third: 16.3 mpg
Middle third: 17.9 mpg
Latest third: 17.4 mpg

The first third improved as expected with towing removed, but so did the second. What else was different about that middle third?

That's when I went on that extended road trip to Tacoma, the one where I was determined to achieve good highway fuel economy and finally broke the 20 mpg barrier (twice) before finally matching our F-150's highway mpg rating with 23.1 mpg (on a downhill leg with a stiff tailwind.)

No other third featured a 2,800-mile road trip with a maximum fuel economy mission statement, so let's axe those tanks, too.

First third: 16.3 mpg
Middle third: 17.1 mpg
Latest third: 17.4 mpg

Huh. Even after all of that fiddling around, the 10-quart controversy seems to boil down to nothing. There are no detrimental 3-, 2- or even 1-mpg consequences to point to here. This does not explain why our F-150 has underperformed relative to its rated fuel economy.

Here is the overall summary for all miles driven so far:

Worst Fill MPG: 13.3 (towing); 14.0 not towing
Best Fill MPG: 23.1
Average Lifetime MPG: 16.9 (5.9 gallons per 100 miles); 17.2 with towing excluded
EPA MPG Rating: 20 Combined (18 City/23 Highway)
Best Range: 706.6 miles
Current Odometer: 31,725 miles

Dan Edmunds, Director of Vehicle Testing @ 31,725 miles


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