This weekend me and my dad are changing out the thermostat on his truck and will need coolant to do this job. I have noticed on rock auto, the OEM ford coolant is yellow in color.

If I recall correctly, the coolant in his block is orange, which I believe is pretty much dex cool which to my understanding is a crap coolant.

My question is this: Should I drain the whole system and get yellow, or would mixing yellow and orange be ok, or should I just get orange to be safe?

Thanks.

  • Hrothgar_Nilsson@alien.topBEnglish
    1·
    10 months ago

    Here’s a coolant chart from Motorcraft that should help: https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/lubricants/quick_reference_charts/antifreeze_coolants_english.pdf

    Dexcool isn’t “crap”, I think the problems with it early on was with the materials used in the first cars to use it when it was introduced in the 90s, weren’t properly re-engineered from the IAT days (inorganic acid technology aka green). Dexcool is an OAT coolant (organic acid technology).

    The materials that come into contact with coolant have to be properly engineered and have the correct composition to avoid getting eaten away or corroded from a given coolant type.

    The yellow could be HOAT (hybrid organic acid technology) or OAT, the yellow color is just a dye, it is more important to know if your engine takes one or the other and choose accordingly.