How long does a Ford F350 diesel last?

Generally, a Ford F-350 diesel can last well beyond 300,000 miles with diligent maintenance; many owners reach 400,000 to 500,000 miles, and a few report 600,000 miles or more.

Engine design and expected durability

The F-350’s most common diesel powerplant is the 6.7-liter Power Stroke, a heavy-duty V8 designed for long service life under load. Like any diesel, its longevity hinges on maintenance, operating conditions, and how often it’s driven under heavy towing. Routine care, including timely oil changes, fuel filtration, and cooling-system upkeep, directly influences how many miles the engine will accumulate before major repairs are needed.

Why this engine is built for longevity

Ford and its suppliers designed the 6.7L to handle high torque and prolonged workloads. In practice this means robust internals and a cooling system engineered for consistent towing. However, diesel powertrains live or die by maintenance, especially for critical systems like the fuel system, exhaust aftertreatment, and cooling components.

Real-world mileage expectations

Across fleets and private owners, typical reported averages vary by usage. Daily driving with light towing often yields longer intervals between major repairs, while frequent heavy towing and work-use can increase wear on fuel injectors, turbo components, and the transmission. In general, you should expect many trucks to reach 300,000 to 500,000 miles with good care; some even approach or exceed 600,000 miles.

Note: older 6.0L and early 6.7L iterations had different reliability profiles, but the current 6.7L is widely regarded as robust when maintained properly. Always consider maintenance history when evaluating a used F-350 diesel.

Maintenance and driving practices that maximize longevity

Below are the actions with the biggest impact on engine life and reliability. Regular, preventive maintenance is more cost-effective than major overhauls later.

• Adhere to the oil-change schedule using the correct synthetic oil and Ford-approved filters. Diesel engines benefit from clean oil and proper cooling under load.


• Change fuel filters on schedule and monitor fuel quality; clogged filters can reduce fuel rail pressure and stress injectors.


• Inspect and service the cooling system, including the radiator, hoses, water pump, and intercooler; overheating accelerates wear on pistons and turbo components.


• Replace the air filter and maintain the charge-air cooler cleanliness to protect the turbo and intake system.


• Monitor and service the exhaust aftertreatment system (DPF, EGR, SCR components) to avoid regeneration failures and excessive soot buildup.


• Keep the transmission and differential fluids refreshed and within spec if you regularly tow heavy loads; towing can stress driveline components.


• Follow Ford’s service intervals for injectors, turbo, and related systems; address faults early to avoid cascading failures.

By sticking to a rigorous schedule and addressing issues promptly, owners can maximize the F-350 diesel’s service life.

Practical considerations for used-F-350 buyers

When shopping used, consider the truck’s maintenance history, towing duty, and any major repairs. A diesel that has been routinely serviced, with documented oil changes and fuel-system maintenance, is more likely to reach higher mileages than one with spotty service records.

Watch for signs of wear that can hint at looming failures, such as excessive oil consumption, blue or white smoke, coolant contamination, or persistent hard starting.

Signs of wear and when to service

Being proactive about maintenance can prevent early failure and protect longevity. The following indicators warrant prompt attention and a diagnostic check with a qualified technician.

• Unusual engine noises, knocking, or persistent misfires


• Significant coolant loss or oil leaks


• Persistent low oil pressure or failing oil pressure readings


• Excessive exhaust smoke (blue or black) and poor acceleration


• Fuel-system warnings or injector issues

Addressing problems early helps keep a diesel engine healthy and extends its life.

Summary

The Ford F-350 diesel is built to endure heavy-duty use. With disciplined maintenance, owners commonly reach 300,000–500,000 miles, and many report 600,000 miles or more. The key to longevity is proactive care, prudent towing practices, and timely attention to fuel, cooling, and exhaust systems. For potential buyers, a well-documented service history is the best predictor of long-term reliability.

Bottom line takeaway

For the Ford F-350 diesel, longevity hinges on maintenance, usage, and driving context. Proper care can yield a decade-spanning, high-mileage workhorse, while neglect can shorten its life significantly.

Is it worth buying a diesel with 200k miles?

Buying a diesel with 200k miles can be a good value if it has a thorough maintenance history and has already had major components like fuel injectors, the turbo, or a transmission replaced. However, it is a gamble; the engine may be near a major repair, and you should prioritize inspecting the vehicle for signs of rust and poor maintenance, and consider the vehicle's intended use and if any previous modifications could be issues.
 
What to look for

• Maintenance records: A history of regular maintenance is crucial. Look for evidence of replaced parts like fuel injectors, glow plugs, and head gaskets, especially if the vehicle is an older model that is known for those issues. 
• Major component health: Diesels with 200k miles have likely had or will need major repairs. Check for signs of a healthy turbocharger (no whining), evidence of transmission work (especially if it's an automatic), and that the suspension and steering components are in good shape. 
• Emissions systems: Newer diesel trucks have complex emissions systems that can be problematic. A truck that has been "deleted" might be a better option, but be aware of the legality of this in your area and the potential for future issues if you need to pass emissions testing. 
• Rust and frame integrity: Check the frame for rust, which can be a deal-breaker regardless of the engine's condition. 
• Hours vs. mileage: For commercial trucks, the number of idle hours can be a better indicator of wear than the total mileage. 

Why 200k miles might be acceptable

• Value: At 200k miles, the vehicle may be significantly cheaper, and many of the expensive repairs have already been done by a previous owner. 
• Longevity: Properly maintained, many diesel engines can last well beyond 200k miles. 

Why it might be a risky purchase

• Unexpected repairs: A 200k mile diesel truck may be on the verge of needing major and expensive repairs. 
• Emissions system failures: Newer trucks have emissions systems that are expensive to repair if they fail. 
• Rust: If the truck is from a rust-prone area, it's at higher risk for frame damage, which can make it a poor investment. 

Final thoughts

• The decision depends on a combination of the truck's price, its maintenance history, and the potential for future repairs.
• For a collector, a lower-mileage truck will always command a higher value.
• For a practical driver, a 200k mile truck can be a smart purchase if it has been well-maintained and the price reflects its condition. 

How many miles can you put on a Ford F350 diesel?

Maintenance Is Important to Longevity
That said, while most gas engines are intended to last at least 200,000 miles on average, a diesel truck that is well-maintained can potentially last 350,000 to 500,000 miles.

What is the life expectancy of a Ford 6.7 diesel engine?

A properly maintained 6.7 Powerstroke engine can last well over 200,000 miles, with many owners reporting 300,000 miles or more. However, its lifespan depends heavily on regular maintenance, especially oil changes, fuel filter replacements, and ensuring the engine reaches operating temperature to prevent issues like fuel dilution. Factors like emissions equipment and the quality of any modifications also play a significant role.
 
Key factors for longevity

• Regular maintenance is critical: Change the oil and filters consistently, using high-quality fluids and parts. 
• Drive to warm up the engine: Avoid frequent short trips that prevent the engine from reaching its optimal operating temperature. This helps with the emissions system and reduces fuel dilution. 
• Address emissions equipment: While newer emissions systems are less problematic than older ones, the Diesel Particulate Filter (DPF) and Diesel Exhaust Fluid (DEF) system are still components that require maintenance and can have a finite lifespan. Some owners opt for DPF/DEF delete kits, but proper installation and maintenance are still crucial for a long life. 
• Monitor and upgrade the turbocharger: Early models had more frequent turbo failures due to a turbo that was potentially undersized. Newer models are generally more robust, but turbos are still wear items that can be stressed by modifications. 
• Maintain the cooling system: Keep the cooling system in top shape and watch for leaks, especially around the coolant pressure cap. 
• Use high-quality fuel and additives: While not a replacement for good fuel, using additives can help with fuel system health. 

Are Ford F350 diesels reliable?

Many owners have dealt with major engine failures, fuel dilution in the oil, and recurring problems in the diesel particulate filter and exhaust systems. Repairs are costly, and reliability is a frequent complaint. 6.7L (2011–Present): Ford made notable improvements with the 6.7L engine.