UPDATE:
Did some testing with my mock up "
Off Road Racing" Waste Solvent System fuel system.
I should be able to burn up to 20% of total engine fuel mass combined. Possible 30% during Summer months.
The main solvent is Toluene, around 70% in the waste solvent IM getting and has a Specific Gravity of 0.865 so pre-heating is a must.
This should save me a ton of $$$ running this system on pump premium 92 Octane verse racing fuel.