15. Cummins B Series Diesel
The Cummins B Series, particularly the 5.9L variant, is an icon in Dodge Ram trucks and agricultural equipment alike.
Renowned for its industrial-grade durability and straightforward design, this diesel engine is known to effortlessly rack up several hundred thousand—and sometimes even a million—miles.
As Diesel Power Magazine highlights, the B Series has become a legend among heavy-duty truck owners, prized for its longevity and ease of maintenance.