2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/195246Based on the {\it dynamical} equivalence between higher order gravity and scalar-tensor gravity the PPN-limit of fourth order gravity is discussed. We exploit this analogy developing a fourth order gravity version of the Eddington PPN-parameters. As a result, Solar System experiments can be reconciled with higher order gravity, if physical constraints descending from experiments are fulfilled.6 pages, Phys. Rev. D accepted versionAstrophysicstext