Low conversions of propane, n-butane, and 2,2-dimethylpropane were measured with each reactant in the presence of iron-and manganese-promoted sulfated zirconia in a once-through plug-flow reactor at 101 kPa, 473-723 K, and reactant partial pressures of 25, 250, and 1000 Pa. Rates of the reactions (overall conversion of propane, of n-butane, and of 2,2-dimethylpropane; formation of methane from each of the three reactants; formation of ethene from propane and from n-butane; and formation of ethane from n-butane) were determined by extrapolating the declining conversions to zero time on stream. The apparent activation energies and apparent pre-exponential factors characterizing these reactions, which are inferred to proceed via carbonium-ion transition states, fall near a straight line on a compensation effect plot. The plot is suggested to represent the family of reactions proceeding via protolytic cracking and dehydrogenation and carbonium-ion transition states.