Any benefit to keep volt meter hooked up and drive around, to test if anything going on in different RPM's and speeds/gears?   Read alot people that trans govenor seems to come into play with a/c leakage.  When using cruise control my actual mph gains on flat stretches.  I can set it at 65 and 3 or 4 miles later I'm going over 70.  Haven't tested anything yet but think it might be a/c  leakage,  reason why I'm wondering about higher speeds/RPM's.

Thanks

You could but in a nutshell you'll find the bigger the electrical load higher the AC voltage. Faster the RPM the higher the frequency.