2024: Thoughts on the sweet spot in the M20 model range?

[natdm]

7 minutes ago, BlueSky247 said:

 

You would think that seat option would be more common!

 

Regarding that C - I assume it was cooler out? Tanks not full? Are you both scrawny people?  

It's AZ. One leg was out of Tucson (RYN). Probably 4000 density altitude (edit: this is not right, I forgot Tucson is lower than Phx, probably 2000?), 350lb total in the seats, half tanks. Still well off before the markers.

[Fly Boomer]

9 hours ago, natdm said:

And for the C, a friend on here has one. We went flying recently and he was off well before the 1000ft markers each time, whereas I'm off just after them. It was amazing and I was jealous.

Keep climbing until you reach the low twenties -- you'll feel a lot better.

[Falcon Man]

Additional info on my K model comparisons 65% HP:

For the 252/Encore and 262 =  MP 26-28 inches, RPM 2200, FF ~ 11 gph.

For the 231 = MP ~ 28-30 inches, RPM 2200, FF ~ 12 gph.

When temps were higher than std the MP and FF would go up proportionally.

[hubcap]

8 hours ago, Falcon Man said:

Additional info on my K model comparisons 65% HP:

For the 252/Encore and 262 =  MP 26-28 inches, RPM 2200, FF ~ 11 gph.

For the 231 = MP ~ 28-30 inches, RPM 2200, FF ~ 12 gph.

When temps were higher than std the MP and FF would go up proportionally.

On my 231, I typically run LOP @ 65% power, 28” MP (with intercooler), 2400 RPM, and fuel flow is 10.0 - 10.2 gph.  TAS - 170-175kts at 17,000 ft

[Pinecone]

9 hours ago, Falcon Man said:

Additional info on my K model comparisons 65% HP:

For the 252/Encore and 262 =  MP 26-28 inches, RPM 2200, FF ~ 11 gph.

For the 231 = MP ~ 28-30 inches, RPM 2200, FF ~ 12 gph.

When temps were higher than std the MP and FF would go up proportionally.

If those are LOP numbers, you were running the 252 at 72% and the Encore at 68-69%.

The 231 was at 78%.

When LOP for a 7.5 to 1 compression ration, you are making 13.7 HP per 1 GPH.  So 11 GPH =  150.7 HP

[Falcon Man]

My JPI showed the percent HP during these flights. Perhaps these three were not calibrated correctly? Seems unlikely.

The performance numbers I recorded were referenced, for example:

In my current 252 my numbers are referenced from the Mooney 252 POH Cruise Power Schedule for the 252, which shows 65% power at 136.5 BHP, 2200 RPM, MP 26 ", at STD temp of -21 C. @ 18K altitude, w/ FF of 10.5 gph, assuming leaned to peak TIT. However I was usually just ~ 25 degrees LOP.

Interestingly all three airplanes FF was 0.5-1.0 gph higher than the performance charts in the POH's.

Not sure where your 231 data comes from because the LB engine can't produce 78% power at 2200 rpm as the critical altitude is 14,000 ft, unlike the MB which is 24,000 ft.

IMHO and experience.

[Falcon Man]

Regarding range in K models w/ standard fuel tanks, at 65% hp up to 1000 miles, endurance ~ 6 hrs. 

[Falcon Man]

After flying a B, G, E, J and K models I stuck with the K because it fit my mission the best.

West of the Rockies is where most of my flying occurs @ 16,500-17,500 altitudes which are a great place to be for cross country flights out here. I usually fly with just me and baggage so useful load is not a large concern.

The turbocharged engine allows me the ability to maintain decent speeds, puts me above the turbulence in the warmer months, gives great clearance over the mountain ranges, allows continuous radio communications, provides significant glide time in the case of engine troubles, has the same cabin seat space as the long bodies without the added expenses in maintenance and insurance.

Logically speaking the FF argument loses importance when compared to the maintenance, insurance, hangar and upgrade costs.

As others have said repeatedly, pick the airplane that fits your mission. 

[BlueSky247]

Thanks everyone for the continued education. Much appreciated! 

It seems like an F, J or K would fit what I'm looking for. I would like to be able to do Angel flights later on, so I will for sure need to pay attention to useful load and range.

[Pinecone]

2 hours ago, Falcon Man said:

My JPI showed the percent HP during these flights. Perhaps these three were not calibrated correctly? Seems unlikely.

The performance numbers I recorded were referenced, for example:

In my current 252 my numbers are referenced from the Mooney 252 POH Cruise Power Schedule for the 252, which shows 65% power at 136.5 BHP, 2200 RPM, MP 26 ", at STD temp of -21 C. @ 18K altitude, w/ FF of 10.5 gph, assuming leaned to peak TIT. However I was usually just ~ 25 degrees LOP.

Interestingly all three airplanes FF was 0.5-1.0 gph higher than the performance charts in the POH's.

Not sure where your 231 data comes from because the LB engine can't produce 78% power at 2200 rpm as the critical altitude is 14,000 ft, unlike the MB which is 24,000 ft.

IMHO and experience.

10.5 GPH is 65/4% power when LOP.   That tracks.    I run my 252 at 29.5", 2300, 10.1 GPH, but that is just under 65% power.

The numbers previously reported were at higher power settings.

For the 231 I used the numbers you posted.

"For the 231 = MP ~ 28-30 inches, RPM 2200, FF ~ 12 gph."

12 GPH is 164 HP or 78.3%,  Unless that was ROP.