Mooney M20K 231 / 252

Mooney introduced the M20K 231 in 1979 as the turbocharged variant of the M20J 201. The 231 used a Continental TSIO-360-GB at 210 hp turbocharged, replacing the M20J's normally-aspirated Lycoming IO-360. The TSIO-360-GB was a successful production engine but ran without an intercooler or automatic wastegate, which meant pilots had to manage CHTs and TITs manually during operation. The original GB had documented durability issues that surfaced as cylinder wear and turbo failures.

Mooney introduced the M20K 252 TSE (Turbo Special Edition) in 1986 with the upgraded Continental TSIO-360-MB. The MB engine had an intercooler reducing cylinder inlet temperatures, an automatic wastegate simplifying pilot workload, and refined accessories. The MB engine reaches TBO routinely where the earlier GB engine often required mid-cycle work. The 252 became the better M20K for buyers willing to pay the premium.

Mooney also produced the 252 Encore in 1997-1998 as a brief production restart of the M20K line with the same TSIO-360-MB engine and minor refinements. The Encore is essentially identical to the late-production 252. Total M20K production was about 700 aircraft across all variants. The fleet has remained popular with pilots who want turbocharged altitude capability in a Mooney airframe. Mooneyspace.com covers the M20K family with substantial type-specific knowledge.

The M20K cruises at about 200 KTAS at FL200 burning 13 gph of 100LL. At lower altitudes, cruise drops to 175 KTAS at similar fuel burn. The turbocharger maintains rated power to about FL220. The M20K is one of the most-efficient turbocharged singles available, with mid-200 KTAS cruise at modest fuel burn relative to other turbocharged singles. Service ceiling is FL250 on paper, which provides meaningful altitude flexibility for cross-country missions.

Useful load on an M20K is about 950 to 1,000 pounds, similar to non-turbo Mooneys. Full fuel (75.6 gallons usable on most variants) leaves about 500 to 550 pounds for people and bags. The compact Mooney cabin works for two adults plus full bags. Four adults plus minimal bags fits with careful loading. Range with reserves is about 1,100 nm at long-range cruise. The M20K's combination of altitude capability, cruise efficiency, and range makes it one of the most cross-country-capable piston singles in its acquisition range.

The Continental TSIO-360-MB (M20K 252 and Encore) or TSIO-360-GB/LB (M20K 231) is the engine on the M20K. Six-cylinder, horizontally opposed, fuel-injected, turbocharged piston rated at 210 hp. Continental's published TBO is 1,800 hours (2,000 hours for serial number 1006000 and later) per Continental Service Information Letter SIL 98-9E.

Field overhauls at Western Skyways, Mattituck, or other reputable Continental turbo shops run $42,000 to $60,000 in 2026 prices. The TSIO-360 family has decades of fleet experience across the M20K, the Piper Seneca II/III/IV/V, and the Turbo Dakota. Parts and shop expertise are reasonable. The intercooled TSIO-360-MB in the 252 has meaningfully better durability than the original GB.

Oil consumption on a healthy TSIO-360-MB runs about 0.4 to 0.6 quarts per hour. The engine demands disciplined CHT and TIT management during operation. Cylinder work at top-overhaul intervals (around 1,000 to 1,300 hours on hard-flown engines) is more common on the GB than on the MB. The TSIO-360-MB with intercooler is the better long-term choice for buyers who plan extended ownership.

Plan on $230 to $325 per flight hour at 100 hours a year of utilization, all-in. The M20K's operating cost is meaningfully above naturally-aspirated Mooneys due to the turbo. Fuel and oil run about $73 to $93 per hour at 13 gph and $5.50 to $7 for 100LL. Engine overhaul reserve is $23 to $33 per hour. Prop overhaul reserve adds $1.50 to $2.50 per hour. Airframe maintenance reserve is $35 to $55 per hour due to gear, fuel tank, and turbo system maintenance.

Annual fixed costs (hangar, insurance, annual inspection) add another $70 to $120 per hour at 100 hours a year of utilization. Insurance is meaningfully higher than non-turbo Mooneys. First-time turbo retract owners pay $3,800 to $7,000 a year typically. Established M20K pilots pay $2,500 to $4,500.

Acquisition cost in mid-2026: M20K 231 aircraft trade $130,000 to $185,000. M20K 252 TSE aircraft trade $170,000 to $230,000. M20K 252 Encore aircraft trade $195,000 to $245,000. The intercooled 252 trades $30,000 to $50,000 above comparable 231s for good reason: the durability and operating-cost advantages are real.

Mooneyspace.com and Mooney Caravan provide essential type-club support. The M20K specifically benefits from community guidance on engine operation discipline, intercooler benefits, and the various engine variants over the production run.