Ford's Better Idea

Spurred on by the Arab oil embargo and the demands of The Energy Policy and Conservation Act, automotive engineers in the past few years have improved fuel economy by cutting down the weight of cars, designing lean-burning, "stratified-charge" engines and developing electronic ignition systems that fire spark plugs at precisely the right time in the engine cycle. Last week the Ford Motor Co. revealed that it had developed still another way of saving gas. Ford President Lee lacocca announced that within two years, his company will offer six-cylinder vans and light trucks equipped with a device that will automatically shut off fuel to three of the engine's cylinders when the vehicle reaches cruising speed. Ford's better idea will cut gas consumption by at least 10%.

As long ago as 1917, drivers of Enger autos with V12 engines could shut off fuel to six of the cylinders by moving a lever protruding through the dashboard under the steering column. Ford has substituted electronic for human control in its "dual displacement engine" (DDE). A small (6 in. by 6 in. by 1-c- in.) black box mounted on the fire wall is fed information from five strategically placed sensors. These devices monitor the temperature of the engine coolant, the engine speed, the transmission setting, the engine manifold vacuum pressure and the throttle angle.

When the sensors inform the electronic brain that the engine has reached operating temperature (180DEG F.), that the auto is in third gear, has reached 45 m.p.h., and is not accelerating, the little box sends out a signal activating a key-and-slot device that locks the exhaust and intake valves shut and cuts off fuel to the affected cylinders. The pistons in these cylinders continue to move up and down, and the spark plugs fire, but no fuel is burned. The cylinders are not supplied with the fuel mixture as long as the driver maintains cruising speed or until the vehicle's speed drops below 25 m.p.h.

Noiseless Shift. TIME Correspondent Ed Reingold last week drove a Ford van equipped with a DDE engine. His report: "If you didn't know the cutout engine was in the car, you probably would not even feel the difference. When you know, you are conscious of the car's being in the six-cylinder or three-cylinder mode only at certain points; you feel a small, noiseless shift."

Ford also intends in due course to make the new system available in passenger cars. Engineer James Clarke, who heads the DDE project, is already driving a car equipped with an eight-cylinder version. On a highway trip, he believes he might be able to cut fuel consumption by as much as 20%.

This file is automatically generated by a robot program, so viewer discretion is required.