Dieselsite 203° Thermostat - 7.3L - 1996-2003 Ford F-Series

Dieselsite 203° Thermostat – Ford 7.3L Powerstroke (1996–2003)

The Dieselsite 203° Thermostat restores your 7.3L Powerstroke to the operating temperature it was originally engineered to run at. Navistar designed the 7.3L Powerstroke to operate at 203°, not the lower temperatures used in later Ford revisions.

This thermostat uses the correct long-stem design for 1996–2003 water pumps while restoring the proper 203° operating temperature, giving you the benefits of improved combustion efficiency, cleaner operation, and better overall engine performance.

🔥 Why 203° Matters:

• 203° is the original Navistar-engineered operating temperature

• Improves fuel atomization and combustion efficiency

• Reduces cold-running issues common with lower-temp thermostats

• Helps maintain proper oil temperature and engine cleanliness

• Prevents giving up performance due to under-temperature operation

🛠️ What Makes This Thermostat Different:

• Correct long-stem design for 1996–2003 water pumps

• Properly calibrated 203° temperature spring

• Eliminates the compromises of 192°–195° aftermarket replacements

• Designed specifically for the 7.3L Powerstroke cooling system

📌 Important Fitment Notes:

• Fits 1996–2003 Ford 7.3L Powerstroke trucks

• Engine Serial Number 201681 and newer

• Not for use on 1994–1995 trucks unless a 1996–2003 water pump has been installed

📦 Part Number:

• DS203

If you want your 7.3L Powerstroke to run the way Navistar intended, this is the thermostat that belongs in your truck. No compromises — just correct operating temperature and reliable performance.