Process to maintain high solvency of recycle solvent during upgrading of steam cracked tar

Processes for improving hydrocarbon feedstock compatibility are provided. More specifically, a process for preparing a liquid hydrocarbon product includes heat soaking a tar stream to produce a reduced reactivity tar and blending the reduced reactivity tar with a utility fluid comprising recycle solvent to produce a lower viscosity, reduced reactivity tar. The process also includes hydroprocessing the lower viscosity, reduced reactivity tar at a temperature of greater than 350° C. to produce a total liquids product containing the liquid hydrocarbon product and the recycle solvent. The process further includes separating the recycle solvent from the total liquids product, where the recycle solvent has the SBN of greater than 110, and flowing the recycle solvent to the reduced reactivity tar for blending to produce the lower viscosity, reduced reactivity tar.