A full-size 4-cylinder sedan with few, if any, compromises
By Huw Evans
Just a few years ago the very notion of a 2.0-liter four-cylinder engine in a full-size car that weighs around 4,000 lbs would have been absolutely absurd. In fact, it still is. And yet here we are, behind the wheel of just such a machine.
The 2013 Ford Taurus, equipped with a 2.0-liter four-cylinder engine, might appear to echo the slow-selling Five Hundred from 2005, a car that was not only virtually invisible in the marketplace, but which was powered by a 3.0-liter V6 that developed a meager 203 horsepower.
And yet in the new Taurus, when punching the throttle in order to merge with traffic on the Southfield Freeway in Dearborn, there’s definitely a decent amount of pep under that contoured hood.
According to Raj Nair, who’s succeeded Derrick Kuzak as Ford’s vice president of Engineering and Global Product Development, the 2.0 EcoBoost powered Taurus is aimed at people “who want fuel-efficient vehicles but don’t want to sacrifice power, cargo space or convenience preferences to get them.”
Besides Taurus, the 2.0-liter EcoBoost four-cylinder motor is offered in the Explorer, Escape and also the high performance Focus ST hot hatch.
LIGHT AND TORQUEY
For starters, using an aluminum block and cylinder head, it weighs around 55 lbs less than the regular Taurus’ 3.5-liter V6. Featuring a relatively high compression ratio (10.0:1) and high pressure fuel system with seven jets for each injector, plus a Honeywell turbocharger with a low inertia rotor that spins at speeds of up to 195,000 rpm
, boost builds up rather quickly at low rpm
, to the point that this engine is making its maximum 270 lb-ft of torque at 3000 revs.
Even a decade ago, the very notion of a high compression, turbocharged engine, especially one that can deliver that kind of V8 like thrust at low rpm
, would have been barely conceivable, especially in a full-size, production sedan like this.
However, according to Taurus program engineer Robert Kay, forcing fuel at high pressure directly into the combustion chamber, combined with the small diameter turbocharger, essentially mitigates the chance of detonation while improving airflow and burning. As a result, higher compression ratios can be utilized in conjunction with relatively high boost levels (16 psi
). To give you an idea, on Ford’s very first turbocharged engine, the 2.3-liter Lima four, which debuted for 1979 in the then new Mustang, boost was limited to just 6 psi
to prevent knock. Perhaps even more impressively, the 2.0 in the Taurus has also been designed to run on regular grade fuel, just like every other EcoBoost engine.
In an effort to maximize efficiency and fuel economy, the 2.0-liter EcoBoost sports a one-way alternator clutch and a low-tension accessory drive, plus Ford’s Electric Power Assisted Steering (EPAS
) to reduce parasitic loss on the engine.