Maurice E. LePeras letter to the editor in January serves to cloud the first synthetic automotive oil issue, when in fact the issue is clear. Steve Swedberg had it right by citing Amsoil as first.

Credit for development of the first synthetic oil for automobile engines has been assigned, on rare occasion, to one source or another. Invariably, however, the criteria used to support that credit lacks any concrete point of reference. While it is true that the U.S. Army experimented with synthetic oil in 1967, the Army was not alone. Others were experimenting, as well. Amsoil President Al Amatuzios work on synthetic oil began in the early 1960s, and throughout the decade he developed synthetic oils under various names.

The real milestone came in 1972 with Amatuzios development of Amsoil 10W-40 motor oil. That oil was tested at Southwest Research Institute and became the first synthetic motor oil to meet or exceed API Service Classification SE engine test targets. A clearly defined, legitimate benchmark had been established. Amsoil motor oil was tested, proven and documented by a single authoritative source, and for the first time a commercially available synthetic motor oil had been officially designated for use in automobile engines.

With the introduction of Amsoil synthetic motor oil in 1972, the experimental era ended and the synthetic motor oil market opened. Recognition of Amsoil motor oil as the first synthetic oil for automotive applications has been firmly established and universally acknowledged for over 40 years.

Kevin McBride

Amsoil Inc.

Superior, Wis.