PETROL QUALITY

Dominion, Volume 27, Issue 36, 6 November 1933, Page 6

PETROL QUALITY

Recent Tendencies ENGINE EFFICIENCY It was reported in the Press recently that an important body of resellers had. decided that in future they would eliminate second-grade motor spirits from their stations and concentrate only on. selling first 'grade. As they are a large body eloSel.y in touch with motorists’ needs this is a very important decision. This decision has presumably' been - influenced by ta.e steady increases in the efficiency ot.en glnes both in England and U.h.A. It may be of' interest-to the general motorist to mention that the main distinction between first and second grade motor spirits has always been one of volatility. In the simnleSt language this means that a first grade spirit has a lower boiling temperature than a second grade. The most volatile spirits, and hence the most expensive to manufacture, are aviation spirits; next in order are first grade motor spirits, and second grade petrols, with kerosenes last. ’Engine design of recent years has tended to reduce,/, the demand for second grade petrols in ■ England . and U.S.A., and, contrary to popular • belief, for the last three or four years in America the motorist has demanded first grade spirits in every way equal in volatility to the leading brands sold in New Zealand. This better volatility serves to cure a. number of evils such as bad starting, slow pick-up and a tendency for the heavier fractions in second grade spirit to dilute the crankcase oil and damage its lubricating quality*—l’-B.A.