26. Chrysler Slant Six
It’s amazing that Chrysler’s simple yet very dependable and durable six-cylinder engine was produced from 1959 till 2000. Over the course of 41 years, Chrysler made millions of those legendary engines and put them in almost all products it made. Even more so, Slant Six was often seen installed in machines, boats, or trucks, and proved very efficient, easy to maintain, and reliable.

The Slant Six design started life in the late ’50s with 170 cubic inch displacement, which was enlarged to 198 cubic inches soon. In 1960, it became the 225, which was the displacement this engine kept till the end. Chrysler realized the potential of this straight-six and offered an aluminum block option. Chrysler offered multi-carb setups, high-performance parts over the years, and Slant Six even scored victories in NASCAR. Interestingly, Slant Six was very popular in export markets as well.