7.3 Powerstroke Specs – A 2021 Guide

The 7.3 Powerstroke model years range from 1994.5 to 2003 until Ford introduced the 6.0 Powerstroke in 2003.5.

Codenamed the Navistar T444E, the engine got its name from International's T444E model engine since the 7.3 Powerstroke was produced by International Navistar. This turbocharged, direct injection diesel engine is often confused with the IDI engine family since it replaced the 7.3L IDI. 

However, the two engines only share the displacement. - the 7.3 Powerstroke was the beginning of a new engine family.

Ford 7.3 Powerstroke Specs

Let's discuss some of the prominent details about the 7.3:

Cylinder Head

The 7.3 Powerstroke is well-known for its durability, reliability, and longevity. The engine is built from strong and tested materials. The cylinder head itself is made out of cast-iron and features six head bolts on each cylinder for incredible security. 

The only downside of the 7.3 Powerstroke's cylinder head design is poor airflow. Modifying the engine to get around the issue is extremely costly considering the face-value gains.

Block

The 7.3 Powerstroke's durability and reliability are widely praised, even by Cummins and Duramax owners. The solid build and strong materials of the truck are the main reasons. The engine block is no different, it's created out of cast iron, making the engine almost indestructible. 

You won't find any issues with the engine block and cylinder heads other than rare cracks caused by beyond extreme conditions. Mainly for that reason, the 7.3 Powerstroke is still sought out today, and it holds more value than you would expect from a 20 to the 25-year-old truck.

Compression Ratio

The compression ratio of the 7.3 Powerstroke is 17.5:1. 350 PSI is considered optimal in a compression test.

The somewhat high compression ratio of the 7.3 Powerstroke allows the engine to 'extract' more energy from the fuel mixture, causing stronger combustions and creating more power while lowering the exhaust temperature.

The injection control pressure sensor measures the fuel injection pressures and sends the signal to the powertrain control module. The PCM sends a signal to the injection pressure regulator for how much pressure is required to actuate the injectors.

Turbocharger

Depending on the model year, there are three variations of the fixed geometry turbocharger systems for the 7.3 Powerstroke.

The first Powerstrokes ever produced, 1994.5-1997 model years were made with a non-wastegated Garrett TP38 turbo without an intercooler. 

The 1999 model year Powerstrokes received an update to the TP38. An air-to-air intercooler was added for denser air, which meant more horsepower potential and less exhaust gas temperatures. 

The Garret TP38 turbocharger stood out as the best at the time, but your 7.3 Powerstroke will benefit from a modern turbocharger system.

Transmission

From 1994 to 1998, the 7.3L Powerstroke came with two transmission options:

The E40D 4-speed Automatic Transmission

The transmission was based on the C6 design; However, it had computer controls and an overdrive gear next to a few minor features. The transmission is known to be strong and reliable with excellent aftermarket support.

ZF S5-47 5-speed Manual Transmission

The manual option is considered to be superior to Cummins and Duramax trucks from the same model years. It's a great choice for stick-shift enthusiasts.

From 1999 to 2003, the 7.3 Powerstroke received two new transmissions that had an increase in torque capacity:

4R110 4-speed Auto Transmission

The 4R110 was an upgrade to the E4OD, and although they share a similar design, they don't have interchangeable parts. The 4R110 is also known for its reliability, but it won't support high torque output levels unless it's upgraded.

ZF S6-650 6-speed Manual Transmission

This is one of the last transmissions used in pickup trucks due to the advancements made with automatic transmission. The ZF S6-650 can handle up to 520 pounds of torque.

Horsepower

The 7.3 Powerstroke was powerful for its time, but with the advancements in the automotive industry, there are considerably more powerful trucks. However, the 7.3 Powerstroke could be modified to perform the same as a modern heavy-duty pickup.

The newly designed 6.6L Duramax engine had more horsepower than the soon to be replaced 7.3L Powerstroke, but Ford did beat Cummins in the horsepower race.

The horsepower of the 7.3 Powerstroke varies by model year, with the 1994 models coming in at 210 horsepower and the 2001 to 2003 models capping off at 275 horsepower (250 horsepower with the 4R110 automatic transmission).

Torque

Ford was always the king of torque. If you needed anything pulled/towed a Powerstroke engine is a way to do it. Also, Ford was the first one to break the 1000 lb-ft mark with the 6.7 Powerstroke.

The 7.3 Powerstroke beat its competitors, Duramax and Cummins, in the torque race; The 2001 Cummins produces 505 lb-ft, the 2001 LB7 Duramax produces 500 lb-ft, while the 2001 Powerstroke offers 525 pounds-feet of torque with the manual transmission.

Throughout the model years, Ford upgraded the 7.3 Powerstroke's torque output significantly. In 1994, the 7.3 Powerstroke produced 425 lb-ft, and just a couple of years later, in 2001, the truck produced 525 lb-ft.

7.3 Powerstroke Performance

The die-hard fan base that still exists today should tell you just how great of a truck the 7.3 Powerstroke is really. There's not much to dislike; it's a reliable workhorse. However, modern diesel trucks have raised the standard so high that the 7.3 Powerstroke's stock numbers are considered low. What comes next are the countless upgrades to the engine that make it as powerful as a modern Powerstroke at the expense of reliability.

The 7.3 Powerstroke does have its performance roadblocks, especially if you're trying to squeeze big power from the diesel engine. Besides the costly mods, the design of the engine is working against you. The fuel system that was once considered incredible can't stand up to the modern fuel systems. The outdated turbo, the hampered airflow, and a few other obstacles stop the 7.3 Powerstroke from pushing extraordinary numbers. With that being said, the 7.3 Powerstroke can be pushed to 600 wheel horsepower without too many problems, but at that point, you might as well purchase a modern heavy-duty pickup.

If you're looking for reliability, it's hard to top the 7.3L Powerstroke.

Other 7.3L Powerstroke Specs

Here's a quick guide to some common specs people are curious about:

7.3 Powerstroke Oil Capacity: 

The 7.3 Powerstroke holds up to 15 quarts of 15W40 engine oil. The Powerstroke itself holds 13 quarts and the filter holds close to 2 quarts of oil.

7.3 Powerstroke MPG:

7.3  owners report 13 to 15 MPG in the city and 21 MPG at best on the highway.

7.3 Powerstroke Coolant Capacity:

The coolant capacity of the 7.3 Powerstroke is 8 gallons.

7.3 Powerstroke Turbo Specs: 

1994.5-1997 Turbocharger - GARRETT TP38:

• Wastegate system: No wastegate
• Cooling system: No intercooler/cooling system
• Compressor wheel inducer diameter: 59.87 mm (60 mm)
• Compressor wheel exducer diameter: 80 mm
• Compressor housing A/R: 1.10
• Turbine intake wheel diameter: 76.2 mm
• Turbine exhaust wheel diameter: 69.84 mm (70 mm)
• Turbine housing size: 1.15 A/R
• Boost: 14 PSI at max; 2-5 PSI regular driving in 2-4 gear
• Flowrate: Around 1050 cfm

1999-2003 Turbocharger - GARRETT TP38:

• Wastegate system: Does have one, no info about it
• Cooling system: Air-to-air intercooler
• Turbine housing size: .84 A/R
• Boost: 17 PSI at max

Conclusion

Taking into account how much abuse trucks take daily, making a reliable truck is truly outstanding, and Ford was able to achieve that with the 7.3 Powerstroke. The 7.3L holds almost as much value as a modern truck. That’s saying something if we recall that the 7.3 Powerstroke is a 20-year-old truck.