2015 Ford F-150: Oregon Road Trip Leg 5 - A 23.1 MPG Exception, Trip Summary
by Dan Edmunds, Director of Vehicle Testing on September 4, 2015
Finally. I thought it'd never happen. Our 2015 Ford F-150 managed to complete the last 337-mile leg of our trip from Modesto, California to Santa Ana at 23.1 mpg, the first and only time our 2.7-liter EcoBoost-powered 4x4 has matched its EPA highway rating in nearly 18,000 miles of ownership.
But there is huge asterisk. A tailwind persisted for at least two-thirds of the distance — a strong one that had the flags standing straight out. On top of that, I was really trying, never exceeding 65 mph even when the limit went up to 70 mph. I was well aware that this particular leg has historically been the most mpg-favorable of our entire Oregon-and-back route. I was determined to make the best of it.
"Are you on a fuel economy run?" asked my wife at one point in an accusatory tone. It was obvious she wanted to get home as soon as possible.
"No, no," I said. "The speed limit is 65 mph here." This was technically no fib because we weren't in a 70-mph zone at the time.
"Uh-huh," she said, rolling her eyes.
I chose Highway 99 instead of Interstate 5 specifically because there are often three lanes, which made it easier to stay out of the way and let faster cars by without getting bottled up behind semis. I was silently cheering when we encountered one or two bouts of general slowing caused by construction, but at the same time I was never bashful about easing into a faster-moving lane to avoid excess braking that would have killed momentum. And I treated the throttle pedal like it was made of glass when I wasn't using cruise control, which was most of the time.
And we only stopped once, at a rest area with those easy-on, easy-off ramps that lack stop signs or signals.
Modesto sits at an elevation of 87 feet. Our endpoint in Santa Ana is at 115 feet. That part is a wash, but a 4,000-foot pass sits in between. But over dozens of trips, that mountain hasn't stopped this from being, as I said, the most economical leg of our route. I have eclipsed the highway mpg rating of long-term vehicles regularly — sometimes by 3 or 4 mpg — without being near as much of a 65-mph stickler.
I'm not sure why. Perhaps it's because the southbound climb is somewhat abrupt and ends quickly while the descent is long and drawn out. It also helps that Los Angeles traffic, once we descend into it, generally flows smoothly when we arrive after dark on a Sunday evening, yet it never seems to move along faster than 50 mph.
Interestingly, this was a tank of 87-octane regular. Jay Kavanagh, our engineering editor with an engine development background, isn't surprised. It's not that 87 is better, it's more that the high-octane 91 and 92 premium I ran earlier was of no benefit because of the temperature (moderate) and load (empty, not towing).
We're both pretty certain that things would have been different if I'd been towing a trailer up steep mountain grades or been running in extremely hot weather, as we did in a 9,000-mile hot weather octane experiment with a 2011 Chevrolet Cruze powered by a 1.4-liter turbo engine.
Here are the numbers. This final leg's 23.1 mpg resulted from 337.4 miles of very conservative, tailwind-enhanced driving that consumed 14.576 gallons of fuel.
Our entire 2807.7-mile road trip consisted of just five fuel stops, an average of 561.5 miles per tank. Along the way our Ford consumed 139.6 gallons of fuel, which boils down to a trip average of 20.1 mpg. That's an exact match of the EPA combined rating, which isn't much to celebrate since this trip consisted of 95 percent conservatively-driven highway miles.
The trip may well be over, but I've got something brewing that will hopefully put it all in context. Stay tuned.
Dan Edmunds, Director of Vehicle Testing @ 17,765 miles