I know synthetic oils have a higher boiling point, but what is it? And does anyone know if tests have been done on synthetic oil boiling points at 10,000 feet in altitude. I use the 5W50 on a project at 10,000 feet and I believe my oil is foaming/boiling due to lack of pressure. Does anyone have insight?

BIGjay
Just a thought, but I know water contamination can cause foaming or boiling when subjected to a vacuum or in this case high altitude.

Harv

From my experience, I've only seen:
NOACK Volatility, Flash Point, Fire Point and
Pour Point.
RH

IBP of even lousy lube base stock is >500F
bruce

I don't have any specific info, but I would consider the reply regarding water contamination, although you should find a milky color. My personal experience with synthetic engine oils and their volatility is that Amsoil is more stable with lower consumption over time in a leak free, mechanically sound engine than Mobil1. I've used it since 1984. Back then they made a AvOil in the weight you mentioned, but I didn't find it on their website recently.