i ve ran klotz at 25:1 and 32:1. ran AmsOil Pro Saber 100:1 at 40:1 in one motor. all no issues.
but after a few teardowns, the inside of my motors were dirtier than i liked with the klotz. its a good oil, but tends to leave a dirtier look inside.
atm I'm running klotz 32:1 in my ESP 27.2, and Maxam Castor 927 in my TS/ESP Zen 26 reed case. this is the oil ESP recommends and uses.
I'm thinking bout going back to straight amsoil at 32:1 motor seemed to run very well on it, and seems to run cleaner. though i may run another few gallones thru the TS/ESP mtor on the 927, and then open open it up to take a looksee.