Complex sentence: In 1932 Texaco introduced its Fire Chief Gasoline to the public, so named because its octane rating was 66, higher than the US Government's requirements for fire engines.
Split into simpler sentences: In 1932 Texaco introduced its Fire Chief Gasoline to the public. It was so-called due to the fact that its octane rating was 66, which was higher than the US Government's requirements for fire engines.