So far I have 3 gas motors.
RCS 140, BME 44 and a ZDZ40.
My question is:
The ZDZ calls for premium gas and the other 2 call for regular gas.
Can I run them all on premium or will I need 2 gas cans? (1 regular and 1 premium

You can run them all on premium with no problem.
The engines may run a little hotter but not enough to make any difference.

Geistware, I also have a similar situation: ZDZ80RV, G-62, Brison 5.8 & 6.4. You mention that the engine may run hotter with premium (91 octane). I believe you but what is the technical reason? Is it because the higher octane is slower burning? Enlighten me.

Thanks,

Ken