The Dodge Ram 2500 typically uses Mopar OE extended-life coolant (an Organic Acid Technology, or OAT, coolant) in a 50/50 premixed formulation. Engine type determines the exact specification, so always confirm in the owner's manual or with a dealer.
Engine-specific coolant requirements
Gasoline-powered Ram 2500 models and the diesel variant share the general guidance to use OE Mopar coolant, but the exact product should match the engine’s design. Below are the typical approaches based on the two main engine families.
Gasoline-powered Ram 2500 engines
Before you buy coolant, note the following guidelines to ensure you select the correct product for gasoline engines like the 5.7L Hemi or 6.4L Hemi in Ram 2500s.
- Use Mopar Extended Life Antifreeze/Coolant (ELC) Type 2 in a premixed 50/50 formulation with distilled water.
- Choose an Organic Acid Technology (OAT) coolant that is silicate-free and formulated for aluminum engines.
- Do not mix different coolant types or brands; if topping off, use the same product and brand previously installed.
- If draining and refilling, flush the cooling system to remove old coolant and contaminants.
In short, for gasoline Ram 2500s, the recommended choice is OE Mopar extended-life OAT coolant in premixed form, ensuring compatibility with aluminum engine components.
Diesel engine (Cummins 6.7L) Ram 2500
For the Cummins 6.7L turbo-diesel, Ram specifies a diesel-rated coolant with an additive package suitable for heavy-duty diesel use. Use the OEM Mopar diesel coolant or a product that meets Cummins and Mopar specifications, as outlined in the manual.
- Use Mopar Heavy-Duty Antifreeze/Coolant designed for diesel engines, or a coolant that meets Cummins’ EC/HD specifications as stated by Mopar.
- Premixed 50/50 with distilled water is commonly recommended unless the manual indicates otherwise.
- Avoid mixing this coolant with non-diesel-compatible formulas or other coolant types.
- Follow the manual for service intervals and system flushing if converting from a different coolant.
In short, the diesel Ram 2500 requires a diesel-specific OE coolant that meets Cummins/Mopar specifications, with careful attention to mixing rules and service intervals.
Tips for maintenance and replacement
Regardless of the engine, use OEM-recommended coolant and avoid aftermarket substitutes that do not explicitly meet Chrysler/Mopar or Cummins specifications. Always label and store coolant correctly, keep the reservoir capped, and perform regular inspections for leaks, corrosion, or discoloration. If you’re unsure which product you currently have, consult your owner’s manual or contact a Ram service center for confirmation before draining or refilling.
Summary
Bottom line: Ram 2500 coolant decisions hinge on the engine. Most models call for OE Mopar extended-life coolant (OAT) in a 50/50 premixed form, but the Cummins diesel requires a diesel-specific coolant meeting Cummins/Mopar specs. Always verify with the owner’s manual or a dealer, and never mix different coolant types. Proper maintenance, including flushing when switching formulas, helps protect the engine and cooling system for the long term.