In the diesel world, the 6.0-liter and 6.4-liter Power Strokes are legendary for all the wrong reasons. But how bad are they really?  Over the last 2 years, Powerstroke Central has been buying, building, and abusing every generation of Power Stroke to see if the internet hate was justified, creating a real-world test of the world’s most unreliable diesel trucks.

The Reliable Benchmarks

The test started with the icons of reliability. The narrator from the Powerstroke Channel has hammered on his 1996 7.3-liter with performance parts for 20,000 miles. Even with nearly 400,000 miles on the clock, the truck has had zero issues. His 6.7-liter Power Stroke, used for heavy towing, has also been a solid performer, with its only issue being a common oil pan leak after more than 200,000 miles of hard work. These two trucks set the standard for what a dependable Power Stroke should be.

Foregone Conclusion on Unreliable Diesel Trucks

Next came the infamous 6.0-liter. Powerstroke Central pushed their heavily modified truck to the absolute limit, finally spinning a rod bearing on the dyno after a nitrous-assisted pull of 1,137 horsepower. But before that spectacular failure, the truck was surprisingly tough. It endured thousands of miles of abuse and never left him stranded. “I would say the 6.0 will nickel and dime me to death with the little problems,” he said, “but if we are talking about just the bottom end, I would say the 6.0 is the most reliable diesel truck around.”

The 6.4-liter, however, was a different story. Despite being a monster on the street, the truck was a nightmare to own.

“I have had nothing but problems with this truck going through two transmissions in the course of 2 months,” he stated. “I definitely think this truck is hands-down the most unreliable diesel truck ever built.”

The 6.4-liter, however, was a different story. Despite being a monster on the street, the truck was a nightmare to own.

“I have had nothing but problems with this truck going through two transmissions in the course of 2 months,” he stated. “I definitely think this truck is hands-down the most unreliable diesel truck ever built.”

The Final Tally

In this head-to-head abuse test, the reputations held up, but with a surprising twist. The 7.3-liter proved to be the undisputed king of reliability, and the 6.7-liter a worthy successor. The 6.4-liter lived down to its name, proving to be a fragile and frustrating money pit.

The real surprise was the 6.0-liter; while its surrounding systems are notoriously problematic, its engine proved it could handle an incredible amount of abuse before finally giving up, challenging its place on the list of truly unreliable trucks.