Diesel engines, known for their great fuel efficiency ... This makes it harder for a 6.7L Cummins engine to perform at its best, if at all. This is where an engine block heater comes in handy.

In fact, roughly a decade after Cummins began outfitting trucks bearing the Ram badge with engines, it delivered one of the worst diesels in its history, the so-called "53 Block." The notoriously ...