Not radically unconventional, mind you: small engines are arriving in big cars from many makers, and Ford even offered a four-cylinder in the original Taurus of 1986, when gas seemed cheap at a pump price of less than $1 a gallon.
The goal in 2013, of course, is to provide full-size accommodations with something closer to pint-size fuel economy. It is a tactic that makes the Taurus, with a combined city-highway rating of 26 mpg, the country's most fuel-efficient large traditional sedan, according to the Environmental Protection Agency. In second place is the 2013 Toyota Avalon, with a combined rating of 24 mpg; that car has a 3.5-liter V6.
In recent years the once-popular Taurus -- it was the United States' best-selling car five years running and peaked at more than 400,000 in sales twice in the 1990s -- has had a troubled on-again, off-again existence. When its popularity dimmed to near invisibility, it was replaced by the 2005 Five Hundred. But the Five Hundredwas so disappointing that Ford -- in what some saw as desperation -- renamed it Taurus for the 2008 model year.
The base engine in the new Taurus is a 3.5-liter V6 built in Lima, Ohio, and rated at 288 horsepower. In a reversal of the norm, the extra-cost option is a smaller engine, the 240-horsepower 2-liter EcoBoost four-cylinder built in Spain. It costs $995.
The EcoBoost 4 is a relatively advanced engine, using not just a turbocharger but also direct injection of gasoline into the combustion chamber, a design intended to provide more power and better fuel economy. Its torque output of 270 pound-feet tops the V6 engine's 254, and it reaches that peak 1,000 rpm sooner. Both the 2.0 EcoBoost and the V6 engines are paired with attentive and effective six-speed automatic transmissions.
The EcoBoost label, incidentally, simply means it is part of a family of Ford engines in various sizes, all sharing turbocharging, direct injection and a higher price.
To Ford's credit, the 2.0 EcoBoost is a stand-alone option on the Taurus and is available on even the least expensive version, the SE. That model has a starting price of $27,395 with the V6, and adding the EcoBoost engine option inflates the window sticker to $28,390.
With the 2.0 EcoBoost, the Taurus is rated at 22 mpg in town and 32 mpg on the highway. That is 3 mpg better than the standard V6 in both types of driving.
According to the EPA's website (www.fueleconomy.gov), the EcoBoost would save about $250 a year compared with the V6. That calculation is based on 15,000 miles a year (55 percent city driving) and 87-octane gas priced at $3.39 a gallon.
Stated another way, to reap any savings from the 2.0 EcoBoost option, an owner would have to keep the car almost four years -- though it could pay off sooner if gas prices zoomed or if the car were driven an extraordinary number of miles.
The Taurus can be ordered with all-wheel drive, though the 2.0 EcoBoost is available only on front-drive models, including the Limited version that I tested.
The test car had a starting price of $33,795, including a $795 destination charge. Ford then added $6,880 in options, including the EcoBoost ($995); navigation system ($795) and adaptive cruise control and collision warning ($1,195).
There was also a $3,500 package with a long list of features including a heated steering wheel, heated and cooled front seats, heated rear seats, an automatic parallel-parking system, a Sony audio system and blind-spot monitors. The total sticker price was $40,675.
Particularly with all the creature comforts, the Taurus is a pleasant and accommodating large sedan. The front seats are comfortable, a good compromise of soft and supportive, making a five-hour stretch on the road possible.
But rear legroom is only adequate for a 6-foot adult. Its 38.1 inches is 0.2 inch less than in the 2013 Ford Fusion, a midsize car.
The 20-cubic-foot trunk is huge, however.
Ford's notorious and ill-conceived MyFord Touch system continues as the bad boy of ergonomics despite the automaker's attempts at rehabilitation. It is supposed to make controlling everything from the audio system to the climate control easier, but it doesn't. It just makes things that should be simple, like changing the temperature, more complicated.
A voice-control system offers an alternative. But it can be a chore, requiring several steps to do something that one should be able to handle with one twist of an old-fashioned knob.
On my test car, the touch screen sometimes had to be touched several times before the system responded. During one daylong drive, the lower part of the navigation screen went blank for about eight hours, and then returned. Ford said its dealer was not able to duplicate the problem.
Whether on the interstate or on a country two-lane, the Taurus offers a comfortable ride with the kind of dutiful but unenthusiastic handling that one expects from a large family car. For drivers who want a greater level of engagement, Ford offers the Taurus SHO with more power and a sport suspension.
Even with three adults and a trunk filled with luggage, the four-cylinder Taurus easily ambled along at 70 mph on the interstate, and it has adequate power for merging onto freeways among New York City's less-than-forgiving drivers.
The issue is not the car's accelerative potency, but its refinement. Under even moderate acceleration there is a level of four-cylinder noise and vibration that would be marginally acceptable in a modestly priced sedan, but seems out of place in an upscale car like the Taurus Limited.
Over 350 highway miles -- at typical speeds of 65 to 75 mph -- I got 27 mpg. That's a huge 5 mpg less than the EPA estimate, but I was driving in hilly terrain with a heavy load.
Ford is hoping the improvements to the Taurus, as well as the 2.0 EcoBoost engine, will help win sales, which haven't been great.
Through the first 11 months of the year, Ford sold 67,471 vehicles, including some police cars and fleet sales, according to LMC Automotive, a market research firm.
That compares with 159,710 Chevrolet Impalas, 63,572 Chrysler 300s, 74,725 Dodge Chargers and 55,212 Nissan Maximas, LMC said.
The auto industry can be a rude and disappointing arena, and Toyota will try to spoil things with its redesigned Avalon, which goes on sale this month. The EPA ratings for the Avalon with a 268-horsepower V6 will be only 1 mpg lower for both city and highway use than the four-cylinder Taurus.
There will also be a hybrid version of the Avalon with a 4-cylinder engine, which Toyota says will be rated at 40 mpg in town and 39 on the highway. However, the least expensive V6 Avalon will be $31,785, which includes leather upholstery and heated front seats. Direct comparisons can be tricky because of variations in standard equipment.
The least expensive Avalon Hybrid will be $36,350.
In each of the last three years, Toyota never sold more than 29,000 Avalons, which is not much more than a curious footnote in the large-sedan segment.
So, yes, the 2013 Taurus with the 2.0 EcoBoost is a pleasing combination. But the package is hardly compelling because its strongest draw -- the lure of better fuel economy -- is undermined by the extra $1,000 that it costs.