Top panel: Comparison of the MS lifetimes (τ_MS) versus the initial mass (M_ZAMS) for tracks computed with different initial abundances, but the same [Fe/H]. Bottom panel: Relative variation of the MS lifetime with respect to the FRMS scenario (i.e., $100\times \frac{{\tau }_{\mathrm{MS}}-{\tau }_{\mathrm{MS}}(FRMS)}{{\tau }_{\mathrm{MS}}(FRMS)}$), which is indicated by the horizontal dashed line. The points indicate the available tracks