coolant question

[Bfenske]

Do you guys use coolant of a regular 50/50 standard anti freeze/distilled water only or do any of you use a coolant with rust inhibitors added? Just want to know because i'll probably change out the coolant soon on the two volvo diesels on the b31 and was wondering if I should keep it the same as it is currently (no rust inhibitor) or do something different. Just bought the boat so that is why i'm asking.

[Charlie J]

i use straight anti freeze from cat

[Rawleigh]

Use diesel truck antifreeze that has SCA in it to prevent cavitation erosion to the piston liners.