In this paper, REBa 2 Cu 3 O 7-δ (RE = rare earth elements, REBCO) coated conductors with different content of self-assembled BaZrO 3 nanorods were grown by metal organic chemical vapor deposition using a roll-to-roll process. Small changes in chemical composition affecting Ba to Cu stoichiometry induce variation in REBCO c-axis lattice parameter and highly affect the self-field J c at 77 K, superconducting transition width (ΔT c ), and in-field performance of coated conductors. While the self-field J c at 77 K in 15 mol.% Zr-added REBCO film (5 MA cm -2 ) was about 28% higher than that in 25 mol.% Zr-added REBCO (3.9 MA cm -2 ), the in-field J c at 30 K, 3 T (B∥c) of the latter was found to be 36% higher than that of the former. The high J c values of 14.9 and 20.3 MA cm -2 at 30 K, 3 T (B∥c) were obtained in coated conductors with the c-axis lattice parameter of 11.74 and 11.76 A in 15 and 25 mol.% Zr-added REBCO films, respectively.