As low as 0% APR - Buy Now, Pay Later!
On orders over $200
100% Money Back on Select Parts
Red Line WaterWetter 12oz Bottle ( Part Number:RDL 80204)

Red Line WaterWetter 12oz Bottle - Universal

MODEL # RDL 80204
Manufacturer Part # 80204


In stock! Ships same day
Free shipping on all orders over $200.00!

Buy as a package deal and save (5%):
Aluminum Radiator Kit ( Part Number:RSD 02-07RADUP)
Aluminum Radiator Kit - Subaru WRX 2002-2007 / STI 2004-2007
As low as $285.00
View Product
See (11) package deals that contain this product


Red Line WaterWetter is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30ºF. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol-based antifreeze. Or it can be added to new or used antifreeze to improve the heat transfer of ethylene and propylene glycol systems. Water Wetter is designed for modern aluminum, cast iron, copper, brass and bronze systems. It is compatible with all coolants, including the latest long-life variations.
  • Doubles the wetting ability of water
  • Improves heat transfer
  • Reduces cylinder head temperatures
  • May allow more spark advance for increased torque
  • Reduces rust, corrosion and electrolysis of all metals
  • Provides long-term corrosion protection
  • Cleans and lubricates water pump seals
  • Prevents foaming
  • Reduces cavitation corrosion
  • Complexes with hard water to reduce scale
| | | | |


Brand: Red Line
QTY: 12oz
Type: Coolant Additive

Mfgr. Warranty: No Warranty
Condition: New Product
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.



This product has no user uploaded media. You can upload your photo or video of your install by posting a review. Reviews:

great product!
Flushclinker13479 3 years ago
my 2011 WRX was past 60k miles so i flushed the old coolant and put new Subaru 50/50 Super Coolant along with Redline Water Wetter. subaru 50/50 super coolant + redline water wetter = killer combo for spirited/quick driving on street and highway.

Great stuff for the track!
ThorMotoXer518 5 years ago
When I road raced superbikes with the MRA I used this stuff in my HondaCBR600RR and I plan on continuing to use it with my WRX for track days! This stuff is amazing! Most of the tracks I go to don't allow you to use antifreeze incase it gets on the track. With the water wetter, it's a drastic cooling difference over straight water, especially on the hot days. Easy to mix, just follow the directions on the bottle! I will add that during the winter I drain my coolant system and go with Engine Ice antifreeze with 1/2 the recommended amount of water wetter in it as I'm not on the track during the winter months.
Verified Purchase

cool item
Interceptor Porn 6 years ago
good product and high quality, recommended
Verified Purchase

great product
guest55c7a33ccaae52f460946953 6 years ago
Im slowly falling in love with redline the more products I use the more well behaved my wrx is. Dropped overall coolent temp substantially running 50/50
Verified Purchase

great for track use
hanfordcabinet01854 7 years ago
i use this with straight water for the track, it cools better than Glycol, & trust me when I say you don't want anti freeze going on your back tires on the track!! other drivers will appreciate it also. you just have to remember it offers no freeze protection.

  • Q: How much?  justinpozzolo53115 5 years ago


    Ok I have a 2009 sti with the koyo radiator. How much would I need? I drive in really cold conditions so I cant use water..just coolant. Can I mix this with straight coolant? Do I even need this?

    • A: 1 bottle will service a entire system. As for your vehicle, you do not want to run straight coolant as it causes issues with thermal dissipation. As contrary to the name, 100% straight coolant with no water has very poor thermal dissipation properties and needs to be mixed with water. Follow the instructions on the coolant bottle for proper mixing for your vehicles operation conditions.

      Kirill C. 5 years ago
    • A: Oh that's right it isn't straight bad.

      justinpozzolo53115 5 years ago
  • Q: Mixture  sphillips.islreal73402 6 years ago


    So for optimum cooling efficiency do I mix this in equal parts to water? So if I use 1 quart water wetter with 1 quart water?

    • A: Redline recommends 1 ounce of water wetter for every quart of water for maximum efficiency.

      Zach G. 6 years ago
  • Q: Proportion  m1k1e20175 6 years ago


    How much would i need for a stock STI 09 and the Koyo Aluminum Racing Radiators? What would be the optimal proportion? As I understand I can mix it with either water or coolant?

    • A: Redline recommends 1 ounce per quart or 1 bottle for cooling systems with capacities of 12-20 quarts. For optimal cooling you can the same proportion with water only. This WaterWetter will work with water or mixed water and antifreeze.

      Zach G. 6 years ago
Universal Product
This item is non application specific.
Please verify compatibility before purchase. May require some modification for proper installation.