Disclosed is a pyrolysis process that is capable of being with reduced coke and/or tar formation. The process can pyrolyze hydrocarbon feed that contains low- to mid-range levels of non-volatiles. Pyrolysis is carried out with a predetermined amount of the feed being in the liquid phase so as to minimize coke and/or tar formation in the pyrolysis reactor. The pyrolysis feed may also include a diluent, such as molecular hydrogen, that further acts to minimize coke and/or tar formation in the pyrolysis reactor. The amount of diluent in the pyrolysis feed can be adjusted to adjust or control dry point of the hydrocarbon in the pyrolysis feed.