Experimental hydrate dissociation pressures for the nitrogen + methyl-cyclopentane + water and nitrogen + neohexane (2,2-dimethyl-butane) + water systems are reported in the 273.6-277.4 K and 278.2-283.7 K temperature ranges, respectively. The experimental data were generated using an isochoric pressure-search method. Our hydrate dissociation data for the nitrogen + methylcyclopentane + water system agree well with the only set of experimental data published in the open literature. The experimental data for both measured systems are finally compared with the corresponding experimental data in the absence of methyl-cyclopentane/neohexane reported in the literature to study their hydrate promotion effects. (C) 2013 Elsevier B.V. All rights reserved.