Coolant Additive – Gas & Diesel: VP Cool Down™


Cool Down is safe for all gas and diesel radiator systems. It reduces engine temperatures by up to 30°F and improves the flow of coolant. We formulate it for use with today’s OAT and HOAT-formula engine coolants.



Product Description

We formulate VP Cool Down™ coolant additive for both gas and diesel engines. It's safe for all radiator systems and is ideal for racing, street, RV, and tow vehicle applications. In fact, it increases coolant flow for better heat transfer.

Our product not only reduces cylinder head temperatures by up to 75°F but engine temps by up to 30°F! Furthermore, it lubricates all vital components and is approved by most race-sanctioning bodies.

One 16-Oz. bottle of VP Cool Down treats cooling systems of 12-20 quarts. We recommend adding 50% more VP Cool Down for straight water applications. Additionally, diesel applications require twice the usual amount of product.

Cool Down treatments last one year or 30,000 miles, whichever comes first. We do suggest changing your coolant every two years. Moreover, when using it as a diesel coolant additive, we recommend using twice the suggested amount for complete protection of wet sleeve cylinder liners. Another key point is that you should use 2-Oz. of Cool Down for every quart of coolant for Powersports applications.

Another good point is that our coolant additive is a great compliment to Stay Frosty® Hi-Performance engine coolant.

Find out what happened when Engine Labs put Cool Down to the test on a 2006 C6 Corvette.


  • Reduces cylinder head temps 75°F and overall coolant temps by up to 30°F
  • Improves coolant flow for better heat transfer
  • Lubricates all vital components
  • Protects sensitive aluminum alloys


Can you mix this additive with antifreeze?
Yes, you can. Cool Down works great with antifreeze. It is formulated for use with today’s OAT and HOAT-formula engine coolants. We recommend changing your coolant every 2 years.

How do I use Cool Down™?
Just open the bottle and add the contents straight into the radiator or coolant reservoir. If you have access to a radiator cap, pouring Cool Down directly into the radiator is the preferred method. One 16 oz. bottle will treat cooling systems of 12-20 quarts.

Will your coolant additive work in cold weather climates?
If used as directed, it shouldn’t disrupt the freeze protection provided by traditional antifreeze that contains glycol.

Customer Reviews

  • "It does what is claims! With the outside temps going well into the 90s, my car seemed a little hot, choking for air. The coolant was running at 196 degrees at its peak (normal for my car), but my air intake was reading up to 158 degrees. Hot air is no good, so I thought I would try this to lower the overall temperature in the engine bay. It worked!! With my coolant topping off at about 190 degrees, my air intake temp dropped to about 118 degrees at peak. The engine response was noticeable right away!" - Mazda6 / AutoZone customer review on Google
  • "Works as advertised. I added this to a 2000 Ford Explorer 4.0L. The Engine temp ran a consistent 196-201 deg F. After adding this and driving it with the heater on as directed I noticed the engine temp gauge was lower than its usual position. I turned off the heater thinking perhaps the heat draw was lowering the temp. But after driving it another 5 miles the gauge never rose back to its normal position. After 2 days of running the vehicle in the Arizona heat it is still in the same spot. Hooked up an OBD II reader and it read the engine temp at 185 deg F. That’s a whole 11-16 deg cooler than just antifreeze alone. This product does work as advertised. I will put it in again once I perform a coolant change." - Fernando / AutoZone customer review on Google

Additional information

Additional information

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