Thermostat

The 12-valve first-gen Cummins in your Ram is considered one of the best diesel engines ever produced, and for good reason. Fuel efficiency, torque, and simplicity are just a few characteristics that give the Cummins its stellar reputation. We're huge fans of the Cummins engine, which is why we've developed a high-temperature thermostat for the 1989-1993 5.9L 12v Cummins. This Mishimoto thermostat activates at a higher temperature (189.5F) compared to the factory thermostat (180F). By raising the activation temperature, coolant flows through the system later, promoting quicker engine warmup. The Mishimoto high-temperature thermostat is ideal for vehicles in cold climates, where rapid warmup and quicker in-cabin heat is vital. This thermostat includes a high-quality replacement gasket and our signature Mishimoto Lifetime Warranty.

Additional Information

Engine coolant thermostat designed to regulate coolant flow and maintain optimal operating temperature. Ensures efficient warm-up, prevents overheating, and supports reliable performance with a precise fit.

Part Type

Engine Coolant Thermostat

Product Overview

The 12-valve first-gen Cummins in your Ram is considered one of the best diesel engines ever produced, and for good reason. Fuel efficiency, torque, and simplicity are just a few characteristics that give the Cummins its stellar reputation. We're huge fans of the Cummins engine, which is why we’ve developed a high-temperature thermostat for the 1989-1993 5.9L 12v Cummins. This Mishimoto thermostat activates at a higher temperature (189.5°F) compared to the factory thermostat (180°F). By raising the activation temperature, coolant flows through the system later, promoting quicker engine warmup. The Mishimoto high-temperature thermostat is ideal for vehicles in cold climates, where rapid warmup and quicker in-cabin heat is vital. This thermostat includes a high-quality replacement gasket and our signature Mishimoto Lifetime Warranty.

• Higher activation temperature restricts coolant circulation for a longer time, providing quicker engine warmup
• Ideal for cold climates
• Includes thermostat and high-quality replacement gasket

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Product Details

Reference Information

Thermostat, 1989-1993 Dodge 5.9L Cummins High-Temp Thermostat, 87.5C

Mishimoto thermostats are effective in noticeably lowering engine coolant temperatures. These thermostats are built with high-quality wax and are shipped with new rubber gaskets (where applicable) for a good, leak-free seal. They are then digitally calibrated for precise operation. Mishimoto thermostats open up at a slightly lower temperature than OEM or standard thermostats once your engine is fully warmed up. This allows the coolant to flow through the engine sooner, thus reducing and maintaining cooler engine temperatures. Whether you have a daily driver or a modified and upgraded turbo, Mishimoto thermostats will maintain optimal temperatures to efficiently cool your application.