Additives determine most performance criteria so all coolants supplied by a respectable manufacturer will perform well. The one major difference in EG and PG is toxicity. This paper looks at this topic and presents facts for consideration. Because the most persuasive reason to use PG instead of EG based antifreeze is toxicity, we should discuss a little about toxicity. The first thing to think about is the difference between acute and chronic toxicity.
Acute toxicity refers to toxicity that has a short duration.
If you survive poisoning with an acute toxin, there are usually no lasting effects. Chronic toxicity on the other hand is something that lasts a long time. When poisoned with a chronic toxin, symptoms may not appear for a long time and they may last indefinitely. In antifreeze we are most concerned about one time accidental ingestion. Therefore our interest is in acute toxicity.