[Dino's A]

I use antifreeze 50/50 ratio and then I throw in some soluble oil (water pump lube & corrosion preventer) About 1/2 of the small bottle you buy at the parts store. Said that, I knew many a Model A owner that only used soluble oil + water for So. Cal climate and it worked and protected their cars just fine.

But....whatever you do, Do not ever use straight 100% antifreeze AND always use distilled water so you do not put minerals like calcium into your radiator. The calcium will love to clog up your cores in the radiator!