PAG oils have a high flash point and are less volatile than mineral oil meaning less chance of a fire.. They are also very stable at higher temperatures and have a higher viscosity index with very good cooling qualities. Unlike most other motorsports, we run air-cooled engines at 400+ degrees on gas, so those qualities become very important.
When compared to other synthetics, they have advantages and disadvantages like anything else. In many ways it’s a superior base oil but there are two cruical disadvantages. They can’t be mixed with other oils especially mineral oils which can be very problematic if you are an engine builder and your customer doesn’t understand the damage it can cause. Also PAG, in many cases, is miscible with water(water and oil do mix). You don’t want to store your engine with PAG as it can cause corrosion and if you are running methanol, which will pull water from the air, both mix in the oil. Water and methanol don’t make a good lubricates.
I highly recommend a full synthetic oil for all gas applications but not for methanol. Mineral Oils are not miscible with methanol at lower temperature allowing time for the methanol to evaporate or escape through your breather or vent to your catch can. You may still see the oil milk up but it will be far less than a synthetic oil.
