How to Mix Propylene Glycol & Ethylene Glycol

Propylene glycol and ethylene glycol are both used as antifreeze for cars and trucks They are chemically similar in many respects, with propylene glycol considered to be a safer alternative than its ethylene cousin; however, ethylene glycol has better heat transfer properties. Although propylene glycol antifreeze has less coolant ability and is less toxic than ethylene glycol, mixing them won't lessen toxicity or have a major effect on cooling ability.

Things You'll Need

  • Ethylene glycol antifreeze in 1 gallon container
  • Propylene glycol antifreeze in 1 gallon container
  • 5 gallon bucket
  • Fresh water, distilled is preferred
  • Place a 5 gallon bucket on level ground.

  • Pour propylene glycol into the bucket, emptying only half of the 1 gallon container into it.

  • Pour half the ethylene glycol into the bucket.

  • Add in approximately 1 gallon of fresh water, using distilled water as an ideal choice.

  • Pour this 50/50 mixture into your radiator or automotive/truck overflow tank until full.