Ford Applies Cylinder Deactivation Even To 3-Cylinder Engines For Fuel Efficiency

Cylinder deactivation can help boost the fuel economy of a car or truck by shutting down some of its engine's cylinders under light loads.

But what happens when engineers try to add that feature to an engine that doesn't have that many cylinders to start with?

The turbocharged Ford 1.0-liter EcoBoost three-cylinder is already one of the smallest-displacement engines in production; now Ford is experimenting with adding cylinder deactivation.

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The carmaker is assessing whether cylinder deactivation for the three-cylinder engine would be workable, according to Green Car Congress.

Its conclusions thus far were presented by Dr. Andreas Schamel--head of research and advanced engineering for Ford Global Powertrain--at the Vienna Motor Symposium in May.

The main issue with cylinder deactivation on the 1.0-liter engine is the vibration that occurs when some of the cylinders are shut down.

Shutting off one cylinder--which effectively cuts displacement to about 666 cc--results in an uneven firing order, producing unacceptable levels of vibration.

So Ford experimented with "rolling" cylinder deactivation, varying the number and sequence of the deactivated cylinders.

Engineers tested both conventional and rolling deactivation on a Focus equipped with the 1.0-liter engine and a six-speed manual transmission on the roads around Cologne.

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Over 34 miles of city and rural roads, they found that the engine operated in cylinder-deactivation mode "a significant portion" of the time.