Mishimoto Low-Temperature Thermostat - 98.5-13 Dodge 5.9L/6.7L - MMTS-RAM-99L
Can I pick up my order or have it installed at your shop?
Can I pick up my order or have it installed at your shop?
Absolutely. We offer local pickup on most products and full professional installation at our shop in Washington, MO. Whether you just want to grab your parts or have our techs handle the install, we’ve got you covered. Give us a quick call at 636-429-7020 or message us to schedule a visit — we’ll make sure the parts are ready when you arrive.
How do I know if this part fits my vehicle?
How do I know if this part fits my vehicle?
Unsure if it’ll fit? No problem — that’s what we’re here for. Send us your vehicle’s year, make, and model, and we’ll verify fitment before you order. We can also point you toward compatible upgrades or supporting parts if needed.
What if I need to return a product or it’s defective?
What if I need to return a product or it’s defective?
Most unused items can be returned within 30 days in their original packaging. Some products are covered by a manufacturer’s warranty as well. If something arrives damaged or doesn’t meet your expectations, just let us know — we’ll help you get it replaced, refunded, or repaired. (Tracking updates are also emailed automatically once your order ships.)
What's the lead time on custom or fabricated parts?
What's the lead time on custom or fabricated parts?
Many of our parts are built to order — especially fabricated or performance components. These can take additional time to produce before shipping. Lead times vary by manufacturer and demand, but we’ll always keep you updated along the way. If you’re working on a tight schedule, reach out before ordering at 636-429-7020 and we’ll confirm current availability or estimated ship dates.
Description
Description
Mishimoto
A failing thermostat can lead to elevated engine temperatures and potential internal engine damage. Improve the reliability and temperature control of your Cummins cooling system with the Mishimoto Low-Temperature Thermostat for 5.9L and 6.7L Cummins engines.
Designed as a direct-fit replacement for the factory thermostat, this Mishimoto unit features a lower activation temperature of 180°F, compared to the factory thermostat’s 190°F (1998.5–2010 & 2013) and 200°F (2010–2012) activation points. By opening earlier, coolant begins circulating through the engine sooner, helping reduce peak temperatures and maintain more consistent cooling.
This low-temperature thermostat is an excellent upgrade for trucks operated in warmer climates, under heavy towing, or during demanding driving conditions where additional thermal control is critical. Like all Mishimoto performance cooling products, it is backed by the Mishimoto Lifetime Warranty, ensuring long-term reliability and quality craftsmanship.
Features
-
Direct-fit replacement for 1998.5–2013 Dodge Ram 5.9L & 6.7L Cummins
-
Lower 180°F activation temperature for earlier coolant flow
-
Helps reduce and stabilize engine operating temperatures
-
Ideal for warm climates, towing, and high-load driving conditions
-
Backed by the Mishimoto Lifetime Warranty
SKU: MMTS-RAM-99L
