"Old Betsy" Engine
1930
During the Great Depression, consumers desperately needed reliable, cost-efficient products. Knowing that diesel engines were more powerful than gas engines (while consuming about half the fuel), Caterpillar developed “Old Betsy,” a prototype that would become our first diesel engine, the D9900. Within a few years, Caterpillar was one of the world’s largest producers of diesel engines.
As a four-cylinder engine, Old Betsy generated 86.8 horsepower, or 65 kW, at 700 revolutions per minute.
The low-end torque of a diesel engine is what allowed Old Betsy to consume a fraction of the fuel used by a gas engine.
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Old Betsy’s design was so far ahead of the curve that 40 years after its 1933 retirement, it passed 1973 emissions tests.