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The 6.0-liter Power Stroke was a diesel V8 available in Ford Super Duty trucks from 2003 through 2008. It is one of the most divisive engines of all time. Some truck enthusiasts will tell you that a 6.0 is as efficient and reliable as any other Ford F-250 with a Power Stroke engine. Others will claim it canā€™t possibly last to 100k miles. The truth is somewhere in the middle: Ford rolled out this engine quickly to meet 2003 emissions requirements. The result is one of its least reliable modern engines. It is also one of the most talked-about, inspiring many urban legends. But some 6.0 owners do rack up high mileage on their Fords. Read on to find out how.

Lie 1 ā€“ This engine was ruined by tuning for too much power

The engine bay of a 2004 Ford Super Duty with a 6.0-liter Power Stroke V8 engine.
2004 Ford F-250 Super Duty | Cars & Bids

One urban legend about the 6.0 liter Power Stroke is that the International Harvester version is reliable, and Ford ruined it by tuning it for more power. Itā€™s true that the Ford version has additional issues. But these stem from its emissions reduction systems, not its increased output.

There is a grain of truth in this legend. Ford bumped the 6.0ā€™s power about as high as its stock head bolts can handle. Tuning it further without swapping to head studs can often result in a blown head gasket.

Lie 2 ā€“ Itā€™s more fuel efficient than older diesels

The tailgate of an orange 2004 Ford F-250 pickup truck parked in a parking lot, the sky visible in the background.
2004 Ford F-250 | Cars & Bids

This makes sense at first: A 6.0 has less space for combustion (and thus fuel) than the 7.3 it replaced. It also uses newer technology. Engines are getting more efficient every generation.

Take, for example, the 350 cubic-inch V8. The first mass-produced ones were the gas guzzlers in Chevy muscle cars of the 1970s. But the latest is the Ramā€™s 5.7-liter which doubles the mpg of a traditional V8. It uses variable valve timing, cylinder deactivation, and a combined starter/alternator stop-go function to achieve the same mpg in every category as Toyotaā€™s latest V6.

But the story of diesel truck fuel efficiency is far from linear. Ford introduced the 6.0 halfway through 2003 to meet the EPAā€™s tightening restrictions on a smog gas called NOx. While it used the latest tech to reduce emissions and maintain output, it did so at the cost of both mpg and reliability.

The result is that a well-maintained 7.3-liter diesel Power Stroke may get 19 or even 20 mpg on the highway. But a 6.0 will be lucky to see 16. Sadly, the EPA doesnā€™t rank the mileage of heavy-duty trucks, so we have no official confirmation of this, just the testimony of multiple truck owners.

Lie 3 ā€“ The 6.0 Power Stroke canā€™t last a long timeĀ 

2004 Ford F-250 aftermarket gauges | Cars & Bids

Ford Super Duty trucks with the 6.0-liter Power Stroke have a low resale value. Take, for example, the 2004 with just 35k miles that went for under $24k on Cars & Bids (pictured). Similar trucks havenā€™t even fetched $17k. This market leaves many 6.0 owners feeling stuck with their truck. But the answer isnā€™t to throw up your hands, ignore your maintenance, and run your Ford into the ground.

International rated its detuned industrial version of the 6.0 (the VT365) for 350,000-375,000 miles. Thereā€™s no guarantee your Fordā€™s 6.0 will last this long, even if you do everything right (sorry). But if properly cared for, it just may. Some 6.0s have even run up to 500,000 miles on one engine.

Taking care of a 6.0 is no easy task. Driving Line says youā€™ll need to swap oil for the highest quality stuff you can find, every 5,000 miles. You must replace both fuel filters ahead of schedule (15,000 miles) and must monitor or even increase fuel psi to protect the injectors (See Fordā€™s ā€œblue spring kitā€ or PN 3C3Z-9T517-AG). You must clean out and inspect the EGR valve every 20,000 miles. Youā€™ll even need to flush the coolant every 45,000 and throw in an anti-cavitation additive. Youā€™ll probably want to add an aftermarket coolant filter. And you canā€™t even let the truckā€™s two batteries wear out, or they might wipe out the FICM chip and leave you stranded. But, many people who stay on top of maintaining and monitoring a 6.0-liter Power Stroke find it a reliable workhorse for years.

Next, read out Ultimate Guide to the 6.0-Liter Power Stroke or find out more 6.0-liter PowerStroke problems in the video below: