Is 'cost sharing' different between jet and prop powered aircraft? I half remember, sometime in the past, there were different costs in turbine powered aircraft that were allowed to be put into the bucket for cost sharing.

Do I remember correctly or incorrectly?

If this a correct memory, what are the additional shareable costs in a turbine powered aircraft?

addendum:  My ancient brain has come up with some vague answers.  

IE, the hourly payments for engine and airframe maintenance.  This was comparable to rental cost, but because  it is a defined amount in a turbine totally owned by the pilot, it was quantifiable.
I give up.  I have searched and can find no reference in the FARs concerning this question - just the current one about pr0-rate sharing that we all know and love.

Perhaps the 91F and 91K parts have replaced the vaguely remembered item from the 1980s.

Thank you for the opportunity to ask.