Industrial production of mixed tertiary ethers by reacting methanol or ethanol with a mixed tertiary olefin stream is a distinct possibility. Consequently, the synthesis of mixed ethyl tertiary alkyl ethers from ethanol and mixtures of reactive iso-olefins in an isothermal integral packed-bed reader is studied. The rate expressions in terms of activities for the individual reaction rates in this family of ethers are taken from related work. These kinetic expressions are utilized here for comparison with experimental data obtained in a packed-bed reactor containing Amberlyst 15 ion-exchange resin catalyst for a mixed iso-C-6 olefin feed stream as well as for a mixed C-4, C-5, and C-6 iso-olefin stream. Esterification and isomerization conversions increase with space time at the lower temperatures; however, at the higher temperatures equilibrium limitations are approached. As a function of temperature, the conversions first increase and then decline due to thermodynamic limitations for these exothermic reactions. Good agreement is obtained between predictions and experiments.