Although they like to complain about the high cost of avgas and maintenance, most aircraft owners pay only passing lip service to true efficiency. They simply pay what it takes to keep the airplane in gas, oil and parts and let the dollars fall where they may.

Mooney owners are different. They gravitate toward the type because it’s not expensive to buy and goes respectably fast on relatively little gas. Turbocharging can sweeten such efficient performance.

Mooney got into turbocharging relatively late compared to other manufacturers and the first efforts proved somewhat wanting. But that first turbo model, the M20K or 231, overcame initial teething troubles to evolve into the 252TSE, which some…