Engine Oils and Drain Periods

New "Anglia" Range

There are two extremes of operating conditions which can cause a premium type engine oil to become fouled with foreign matter such as fuel-soot, carbon, water etc., rendering it advisable to change the oil and filter before the normal drain period has been reached.

The first extreme is where the car is used for short journeys, involving cold operation and frequent use of the choke, in turn leading to undue sludge formation and oil deterioration generally.

In the second extreme, despite additives present in the oil to control oxidation at high temperatures, sustained high speeds can cause more rapid deterioration, particularly if some sludging is already present as a result of previous stop-start operation. One indication that an engine oil is unfit for further service is its black colour, possibly with beads of moisture which can be seen through the oil filler tube.

Undue wear can occur in an engine where an initially good quality oil has become excessively contaminated and it could be false economy to extend the oil drain and filter change periods beyond the normal drain period.

Some manufacturers make available a type of oil which they state will double the normal drain periods, but whilst this could be feasible in certain conditions, we suggest the present drain period be regarded as a normal maximum.

Oils other than the premium type could be unsuitable for use in the Ford engine because such oils may contain insufficient detergent / dispersant additive treatment, which may lead to heavy sludging and break down of lubrication properties at an unduly low mileage.

Although the engine oils can be mixed with one another, it is generally advisable to use the same grade and brand at all times.