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Mishimoto MMTS-RAM-99L Silver Low-Temperature Thermostat

4.4 (5) Write Review
Free shipping on orders over $29.99

$79.15

$ 37 .43 $37.43

In Stock

About this item

  • Direct fit for 1999-2013 Dodge Ram with 5.9L/6.7L Cummins
  • Activates at lower temperature so coolant flows through system earlier
  • Allows for cooler engine temperatures
  • Ideal for warm climates
  • Lifetime Warranty


A defective thermostat can result in engine overheating and potential internal damage. Improve the reliability of your 5.9L/6.7L cooling system with a Mishimoto Dodge 5.9L/6.7L Cummins Low-Temperature Thermostat! This thermostat is designed as a direct-fit replacement for your aged factory unit. The Mishimoto thermostat has a lower activation temperature (180 degrees Fahrenheit) compared to the factory thermostat (190 degrees Fahrenheit for 99-10 and 2013 trucks & 200 degrees Fahrenheit for 10-12 trucks). The lower activation temperature allows coolant to flow through the engine earlier, which reduces and maintains lower engine temperatures. This thermostat is ideal for use in warmer climates or under extreme towing/driving conditions. As with all our products, this thermostat includes the Mishimoto Lifetime Warranty, ensuring superior product quality and craftsmanship.


Patrick Martinez
Reviewed in the United States on September 30, 2024
Had this in my recently new motor. 5.9 cummins. Thought it would help with cooling. In the beginning it made about a 10 to 15 degrees difference. I thought this is great then about 3 months the truck started to run slightly hot. Checked everything and then came across this. All parts clip backing and retainer have yet to be found. If you buy this buyer beware. Diesel engines are not cheap.
G. M.
Reviewed in the United States on June 5, 2024
It's been in for a while now and is doing good. I had two stock ones fail withing a week. This one has been on two 20 hr trips now.
Max Malyuk
Reviewed in the United States on December 31, 2024
Thermostat decided to self destruct due to poor and weak design
Dennis Timmons
Reviewed in the United States on August 16, 2023
I have an 05 cummins 3500 put a brand new stant 180 thermostat in an fought an overheating issue, replaced rad to mishimoto and did fan clutch and water pump same issues, went to the mishimoto thermostat and cured my issue runs 175-183 in 86* outside, only time will tell about longevity, happy so far
Customer
Reviewed in the United States on August 21, 2019
Easy to install