Designed to stay cool

A unique feature of all petrol-engined Focuses is the ability to run even after the loss of all engine coolant. To increase the fuel economy of the engines, Ford added tempreature sensors drilled into the cylinder head, so that combustion chamber temperature can be modelled very accurately. An added benefit is that if all coolant […]

A unique feature of all petrol-engined Focuses is the ability to run even after the loss of all engine coolant.

To increase the fuel economy of the engines, Ford added tempreature sensors drilled into the cylinder head, so that combustion chamber temperature can be modelled very accurately. An added benefit is that if all coolant is lost, information from the sensors allows the engine management system to switch out cylinders in rotation by cutting the spark and fuel supply. Air pumped through the engine as a result cools the cylinder. The car can be run long enough to get home or to a garage. Wide open throttle over-rides the cut-out temporarily to allow short bursts of acceleration in an emergency.

The Focus comes with Zetec SE 1.4 and 1.6-litre, Zetec E 1.8 and 2.0-litre petrol engines, and a new Endura DI diesel. The Zetec SE 1.4 has been tuned for fuel economy and driveability, giving 6.23mpg more than in its Fiesta guise. Mid-range torque is up 10%. Compression ratio is increased to 11:1 through individual knock control for each cylinder.

A surprising feature is cable-operated gearchange in the manual cars. This eliminates a noise path into the car and takes up less space. ‘We were worried about a sloppy shift,’ says Andrew Shackleton, powertrain systems manager, ‘but we surprised ourselves. It’s smoother than a rod shift.’ Tests have shown it can be assembled in volume production and will retain its precision for the life of the vehicle, he says.