Yanmar Coolant
Yanmar has tested and recommended Texaco products for their small(sailboat auxillary) engines. If you are in warranty, you would be well advised to stick with Yanmar's recommendations.Texaco Long Life Coolant regular and premixed 50/50 products (Code 7997 & 7998) are available in 1 gallon containers. The coolant system should be drained and flushed prior to using. (Including the hot water heater) Do not mix these products with anything other than water.Also acceptable is Texaco Havoline Extended Life (Code 7994). If you choose a full strength anti-freeze, cut if by 50% with preferably distilled water. Dex Cool (Hunter provided) is acceptable, but do not mix it with the above listed products.One of the primary reasons that Yanmar chose the Texaco products was the low silicone content. The standard automotive antifreeze over an extended period was causing failures in the Yanmar fresh water pump. In severe coolant overheating on the engine, the heat exchanger tube bundle is rendered useless because of high silicone content that fouls the tube bundle surfaces. Both casualties are expensive to correct and are not covered under warranty.