The invention is related to compositions suitable for the fabrication of pipes, and other articles, with excellent performance properties. The invention provides a composition, comprising a blend, wherein said blend comprises a high molecular weight ethylene-based interpolymer and a low molecular weight ethylene-based interpolymer, and the high molecular weight ethylene-based interpolymer is a heterogeneously branched linear or a homogeneously branched linear ethylene-based interpolymer, and has a density from 0.922 g/cc to 0.929 g/cc, and a high load melt index (I21) from 0.2 g/10 min to 1.0 g/10 min, and the low molecular weight ethylene-based interpolymer is heterogeneously branched linear or a homogeneously branched linear ethylene-based interpolymer, and has a density from 0.940 g/cc to 0.955 g/cc, and a melt index (I2) from 6 g/10 min to 50 g/10 min. The blend has a single peak in an ATREF profile eluting above 30° C., and has a coefficient of viscosity average molecular weight (CM?) less than −0.0032 in the log(calculated Mv) versus elution temperature, said CMv calculated in the range of elution temperatures from 70° C. to 90° C. The Mv is the viscosity average molecular weight.