RAM recommends the use of a block heater at 0°F/-17°C and mandates its use at -20°F/-29°C. Failure to follow these instructions could lead to premature wear and/or failure of key components, including pistons, rings, and cylinder walls.

We followed RAM's cold start recommendations. Per the owner’s manual, RAM recommends the use of the block heater when the temperature drops below 0°F/-17°C and mandates the block heater at temperatures below -20°F/-29°C.

Using a controlled climate chamber, our first test utilized block heat and two Banks coil heaters (1500 watts total). The Monster-Ram enabled our test truck to cold start down to -30°F/-34°C.

Against RAM’s recommendations, we also attempted to cold start with the same two coil heaters and no block heat. We were able to cold start down to -20°F/-29°C. Adding a third coil heater (2,250 watts total), the truck started at -30°F/-34°C.*

All tests were performed with two intake air pre-heat cycles per the owner’s manual. Intake air temperature is just one factor contributing to a successful cold start. Individual results may vary depending on your vehicle’s age and overall condition. Testing is ongoing with a detailed video forthcoming.

*Battery boosting may be required for sufficient cranking RPM.

Test Vehicle Configuration

• 2024 Ram 2500 4x4 Tradesman, dual cab short bed
• Mileage 7,8XX
• Vehicle unmodified apart from Monster-Ram
• Minimum 12-hour cold soak at specified temperature
• #1 Diesel fuel
• AMSOIL Signature Series 5W40 motor oil
• New Interstate AGM batteries with full state of charge
• New MOPAR fuel filter
• New MOPAR fuel/water separator
• New MOPAR air filter