A Minute That Lasts 20 Hours

Northern Advocate, 29 July 1939, Page 6 (Supplement)

A Minute That Lasts 20 Hours

The first minute after a car stai’ts on a very cold morning can produce as much engine wear as twenty hours oi ncn-stcp driving, if the necessary precautions are not taken. Modern cars have very fine clearances between moving surfaces, and tin's means that the greatest importance is placed on getting an oil on to these surfaces just as quickly as possible after starting. Oil recommended for summer use is heavier in body to stand up to hot weather driving conditions, but on a cold frosty morning summer oil is sluggish and circulates slowly. Between starting and the complete circulation of the oil there is a period oi “dry running” during which serious engine wear can occur. Recognising this, oil companies and car manufacturers alike advise the use of a special light bodied oil for winter driving. Tests recently conducted by the Vacuum Oil Company showed that on a cold morning it took approximately 30 per cent, longer to form an oil film after starting when summer oil was in use, than it did when the recommended grade of winter oil was under test. The rate of oil film formation was considered to depend on the rate of oil fling from the connecting rod bearings. This was slowed down considerably when the summer oil was used. It occurred spontaneously with Mobiloil Arctic, an oil specially designed for winter use.

Another interesting fact revealed was that the engine on Mobiloil Arctic started just as easily with the thermometer at zero as with the summer oil at 70 deg. F. To turn the engine over with the summer oil at zerb required just twice as much power as when Arctic was in the sump.

These tests indicate the advantages to motorists in terms of easier starting and reduced wear that lie in the use of the recommended grade of high quality winter oil.