Jeff wrote:
since the new units don't use R12 they need to run a little
longer to do the same job, but do not use as much power to get it done.

Your cause and effect is incorrect.

The new units don't run a little longer "since they don't use R12".
They run a little longer to make them more efficient.

If R12 were still legal, you could build a build a new longer-running
R12 unit. And guess what? It would be MORE efficient than the new
non-R12 units. Why? Because R12 is a better regrigerant than any of
the substitutes. It takes less energy to compress it, and it soaks up
more heat when it expands.