Power Stroke FAQ

Frequently Asked Questions about the Power Stroke Diesel

Who produces the Power Stroke Diesel?

The "Power Stroke" trademark first surfaced with the introduction of the 7.3L Power Stroke, an adaptation of International's model T444E, during the 1994 model year. International-Navistar would go on to develop and manufacturer the 6.0L and 6.4L Power Stroke diesels before Ford and International parted ways. The 6.7L Power Stroke was developed and is produced strictly by Ford Motor Company.

What engine did Ford use before the Power Stroke?

Ford introduced an International 6.9L IDI diesel to the F-250/F-350 platform for the 1983 model year. The design was later revised resulting in a 7.3L IDI, which was offered through 1994.

What's the difference between the 7.3L DIT and 7.3L IDI?

The 7.3L IDI and 7.3L DIT (T44E or 7.3L Power Stroke) are two entirely different engine platforms that share the same bore, stroke, and therefore total displacement. For all intents and purposes, there are otherwise no similarities and the oil cooler assembly is one of few parts carried over. The 7.3L IDI is an indirect injection engine with a completely mechanical injection system. The 7.3L DIT is a direct injection engine with a hybrid hydraulic, electronic injection system.

Does Ford own Cummins?

Absolutely not - Ford does not and has never owned Cummins, nor a majority stake in the company. They did invest in the company in the early 90's, acquiring just under 11% of the Cummins' common stock, which was sold back to Cummins in 1997. Ford has previously offered Cummins engines in their medium duty truck line, which could be where the rumor started.

Why doesn't International-Navistar supply engines to Ford anymore?

The relationship between Ford Motor Company and International-Navistar turned sour as the result of high warranty claims for the 6.0L Power Stroke. Multiple lawsuits were exchanged with regard to which of the two companies should be responsible for the cost of the aforementioned claims. International-Navistar went on to provide the 6.4L Power Stroke, but Ford decided that it was more strategic for them to develop their own engine. In addition to engineering an engine specific to their own needs, Ford has been able to streamline the warranty process. More importantly, Ford's 6.7L Power Stroke has been a huge success for the company and it's reliability is largely recognized.

I'm learning about my Power Stroke diesel but keep coming across acronyms that I don't understand, what is a HPOP?

For your convenience, here's a list of common acronyms that are used in the diesel industry:


High Pressure Oil Pump


Diesel Oxidation Catalyst


Exhaust Gas Recirculation


Diesel Particulate Filter


Indirect Injection


Direct Injection


Direct Injection Turbocharged


Hydraulic Electronic Unit Injector


Selective Catalytic Reduction


Variable Geometry Turbocharger


Powertrain Control Module


Diagnostic Trouble Code


Parameter ID (w/ regard to an OBD-II diagnostic system)


Injector Pressure Regulator


Injector Control Pressure


Manifold Absolute Pressure


Intake Air Temperature


Exhaust Backpressure (w/ regard to EBP sensor)


Common Rail


Charge Air Cooler (synonymous w/ intercooler, aftercooler)


Diesel Exhaust Fluid

Can i shut my truck off during regen?

This is a difficult question to answer and often sparks controversy. Can you shut your truck off during regen? Sure, you can indeed shut your truck off during regen. Should you shut your truck off during regen? Occasionally shutting the engine down during a regeneration cycle is not likely to cause immediate problems. However, it is preferred that owners of DPF equipped trucks not make a habit of interfering with active regeneration cycles. If a regen is occurring at an inconvenient time, it is good practice to allow the engine to idle a few minutes before turning it off. In theory, the engine will read a high backpressure condition and re-initiate the regen at later time. One of the problems with shutting down during a regen is that the turbocharger is extremely hot and ideally needs time to cool before the engine is shut down. When an engine is shut down and the turbocharger temperature is high, oil tends to cook in the bearing channels, reducing turbocharger and engine oil life.

Should I be using synthetic oil?

The two common reoccurring arguments against synthetic oils are that they are 1) overpriced and 2) not recommended for older engines or engines that have been lubricated by conventional oil for tens of thousands of miles. With respect to the first argument, it is true that synthetic oils are typically more expensive than conventional petroleum based "Dino" oils. However, the age rule of "you get what you pay for" could not be more true in this situation. Synthetic oils are less susceptible and more resistant to the three modes of oil breakdown - shear (the mechanical shear force applied to the individual oil molecules), thermal breakdown (the change in molecular structure resulting from exposure to relatively high temperatures), and chemical breakdown (contamination from diesel fuel, blowby gases, etc).

With regard to the compatibility of synthetic oils with older vehicles, all synthetic motor/gear oils are compatible with (can be mixed) convention petroleum based oils and there is absolutely no reason why a high mileage engine would not benefit from a switch to synthetic motor oil. The fact of the matter is that the majority of OEM specifications have ditched conventional oils in favor of more resilient synthetic fluids.

In summary, do you need to use a synthetic oil? No, not unless the OEM specification is full synthetic. Should you use a synthetic oil? Yes, synthetic engine and gear oils are superior in every way, save for a marginally higher cost.

Why would someone swap a Cummins in place of their Power Stroke?

Wow factor? Identity crisis? Your guess is as good as ours. In all seriousness, we've deduced that Dodge Ram owners are typically Cummins customers first. Meanwhile, there's a herd of Cummins diesel enthusiasts who refuse to purchase a Dodge/Ram truck. All bias aside, Ford trucks have obtained historically higher ratings with regard to quality than competing Chrysler products. Therefore, a Cummins powered Ford Super Duty is, to some, the holy grail of trucks.

What is a VGT?

VGT stands for variable geometry turbocharger. A VGT is a single turbocharger that displays the characteristics of both a small and large turbo by altering the A/F ratio of the turbine. This is done by a series of mechanical vanes which open and close to increase or decrease the concentration of energy acting on the turbine wheel.

What is a DOC?

A DOC, or diesel oxidation catalyst, is an emissions control device that converts carbon monoxide and hydrocarbons into water vapor and carbon dioxide through an oxidation reaction. The DOC is typically mounted at the outlet of the turbocharger downpipe and, in complex aftertreatment systems, typically processes exhaust gases upstream of additional emissions equipment. A DOC is the diesel equivalent of a catalytic converter, for all intents and purposes.

What is EGR?

Exhaust gas recirculation (EGR) is the process by which spent exhaust gases are cooled and recycled through the intake of the engine. The EGR process helps to lower the emission of nitrous oxides (NOx), compounds that both contribute to the development of lower atmospheric smog and induce respiratory problems. Ever seen a smog induced "blackout" in China? NOx emissions play a significant role.

What is a DPF?

A diesel particulate filter or DPF is a device used to filter particulate matter from the exhaust stream of a diesel engine. Modern DPFs are highly efficient and capture anywhere between 85% and 100% of soot produced by the combustion of diesel fuel. Since the development of soot is difficult, maybe even impossible to prevent, aftertreatment is necessary to reduce the emissions of these harmful particles. As the DPF reaches max capacity, it enters a cleaning process known as regeneration, regen, or reburn. During the regen process, exhaust gas temperatures are increased and particles accumulated in the filter are burned off.

What is SCR?

Selective catalytic reduction (SCR) is an emissions control process by which NOx emissions are considerably reduced. An SCR system relies on the injection of a urea based exhaust fluid (DEF), which mixes with exhaust gases before entering a catalyst. In the catalyst, a reduction reaction occurs converting nitrous oxides into water vapor and nitrogen gas.

What is DEF?

DEF is a solution of urea (~32%) and distilled water, in addition to additives that promote a longer shelf life. The purpose of DEF is to facilitate the reduction of NOx emissions in the SCR system. DEF is highly corrosive, so great care should be taken in storage and filling of the DEF tank. The use of DEF is mandatory on the 6.7L Power Stroke - failure to maintain the fluid level will result in penalties that include speed limiting and derating of engine power.