Where’s the Eco in EcoBoost?

Ford powertrain engineers may be disappointed to have landed just one 2015 Ward’s 10 Best Engines trophy, for the 1.0L EcoBoost 3-cyl. in the Fiesta.

Dearborn offered up four other engines, and we’d like to explain why they did not make the cut.

2.7L EcoBoost V-6: This all-new F-150 pickup engine is compelling for several reasons, particularly the “hybrid” block construction that uses compacted-graphite iron for the upper part and aluminum for the bottom, as well as aluminum heads with integrated exhaust manifolds.

There are lots of interesting technologies onboard, from the fracture-split connecting rods and variable-displacement oil pump to the structural die-cast front engine cover and deep-set fuel injectors capable of four spurts per combustion event.

Don’t forget the smooth-functioning stop/start system, the composite oil pan, the recycled-material composite cam covers, the premium polymer-coated main and connecting-rod bearings for low NVH or the twin turbochargers with inlet swirl vanes for flow initiation.

This all-new engine architecture incorporates the type of technologies we seek to reward, and this V-6 performs reasonably well, propelling the F-150 with ease and remaining remarkably quiet and composed.

But there’s a big problem: The observed fuel economy is not that good. The EPA says this engine should get 26 mpg (9 L/100 km) on the highway with 2-wheel drive and 23 mpg (10.2 L/100 km) on the highway with 4-wheel drive. Our 4x4 supercab never got close to that, even under a light foot.

Several editors drove the truck for 253 miles (407 km), and the trip computer displayed a low of 17.6 mpg (13.3 L/100 km) and a high of 19 mpg (12.3 L/100 km).

We checked consumption old-school (253 miles divided by 16.16 gallons [61 L] to refill the tank) and came up with an even more disappointing figure: 15.6 mpg (15 L/100 km).

Fuel economy has become a significant measurable as we select Ward’s 10 Best Engines, so it’s difficult to ignore numbers like these.

This engine has impressive power and torque (325 hp and 375 lb.-ft.[508 Nm]). But heck, we’ve driven 5.0L V-8 F-150s that delivered better mileage.

Devoting resources to an aluminum-intensive pickup might pay off in the long run. But no matter how much weight you trim from a fullsize truck chassis, a smallish V-6 will require much work from its twin-turbochargers, which hurts fuel economy.

2.3L EcoBoost I-4: Again, it’s a good effort, yielding 310 hp from this engine derived from the 2.0L EcoBoost already seen across the Ford portfolio. It has an all-new block, and it runs on regular unleaded fuel, just like the F-150 2.7L V-6.

Compelling technologies include a twin-scroll low-inertia turbocharger (a first for Ford) and high-pressure fuel injectors with six holes laser-drilled to help atomize spray into the combustion chamber.

The 2.3L EcoBoost goes hard when called upon, capable of a 60-mph (97 km/h) sprint in 5.2 seconds and a top speed of 145 mph (233 km/h).

In this case, fuel economy was no deal-breaker. Some editors managed 25 mpg (9.4 L/100 km).

The problem with this new Mustang engine is that it doesn’t sound like it belongs in a pony car. Mustangs and muscle-cars in general put off a vibe, even when they’re sitting at a stop light, burbling along, alerting the world that a foot to the floor will ignite fireworks. Even if the driver never runs wide-open throttle, knowing he can is what keeps him in a Mustang.

Start up the 2.3L in the new Mustang, and it sounds thin and even weak, like a pedestrian family hauler. Crank up the revs, and it becomes more engaging. But part of the Mustang’s allure is a great exhaust note no matter how it’s driven.

We asked Ford about this and learned that engineering the Mustang for global markets meant turning down the volume to meet decibel requirements in other parts of the world. So there’s a downside to globalization.

On the upside, the quiet 2.3L EcoBoost is well-suited for the Lincoln MKC utility vehicle, the only other vehicle getting this engine for now.

1.5L EcoBoost I-4: This fuel-sipper in the Fusion is likable, but it’s supposed to be a low-cost replacement for a hybrid. We hoped it would have done better than 29 mpg (8.1 L/100 km), which was the best mileage any WardsAuto editor achieved.

3.2L Power Stroke diesel I-5: The massive Transit van uses this engine, and anyone needing to move a storeful of refrigerators will find it outstanding. It’s reasonably quiet, considering the inside of this truck is like a drum.

Perhaps it wasn’t fair comparing it with the Ram diesel, which clearly is designed for passenger duty. The Transit I-5 delivered admirable fuel economy for a truck this size, averaging 19 mpg (12.3 L/100 km).

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