Stability of the Formation

[Nicole Gamboa 2M]

Hi All,
When doing the Newman Projections and looking at whether a conformation is staggered or eclipsed, I was wondering how you measure the stability of a projection. Is it based on the angles between the substituents or is it based on whether or not the substituents are eclipsed vs. staggered?
Thanks!

[samuelkharpatin2b]

The most stable conformation is when the "bulkiest" substitutents have a 180° dihedral angle between them, i.e. they are on opposite sides of the Newman projection. By "bulkiest" I mean something other than H.

[Nicole Gamboa 2M]

But when you look at the gauche conformation that is staggered with an angle of 60° versus the eclipsed by H conformation where it is eclipsed but the angle is at 120°, which one would be the more stable conformation?

[MariaReina_Garcia_3E]

The gauche conformation would be more stable. Because the eclipsed has steric interactions and I believe torsional interactions.

But when you look at the gauche conformation that is staggered with an angle of 60° versus the eclipsed by H conformation where it is eclipsed but the angle is at 120°, which one would be the more stable conformation?