Bigger 4 cyl or small V6 for highway and hauling

[Ford Man]

I'd say go with the smaller car if it has enough room for everything you have to haul. I've drivien my Escorts with 4 people luggage and about a 100 pound tool box without losing much fuel economy. As for extra wear and tear on the engine, there's very little wear on the engine once it's warmed up at highway speeds. Probably at least 90% if the wear on an engine comes from cold starts. Years ago they claimed the wear from 1 cold start was equal to driving 500 miles with a warm engine. This was back in the 60's and 70's.