Cessna Model 182T NAV III Cruising

Craig R

Craig R

Filing Flight Plan
Joined
Mar 15, 2017
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23
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Bradenton Sarasota
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Display name:
Craig R
The POH really provides no guidance about which RPM and MP to use. It simply provides performance charts. For no reason that I can explain or justify I fly N65995 at 2200 and 22. Seems to provide reasonble performance, noise level and fuel economy, although I won't lean to fuel flow the POH predicts because of all the controversy regarding high temperatures.

What can anyone with thousands of hours in a 182 say about best operating points?
 

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Our old 1972 182p POH has tables of various altitudes, MP, RPM, speed and fuel burn. Doesn't your POH have something similar?

On our carb'd O-470, 22 squared is a great setting at altitudes around 3000msl, burning a bit over 11gph and zero wind ground speeds around 140mph or better. That is leaned until rough and then slightly rich.
 
Join Cessna-Pilots.net. There's a thread in the 182 section regarding operational profiles. I'd link, but you can't see unless you're a member.
 
But that's my point, you can pick many combinations of throttle and prop, given an altitude and a temperature, and most supposedly give you speeds just plus or minus just a few knots and give you fuel economy just tenths of GPH different. How do you know which one to choose? It seems the same as driving 45 mph in 4th, 5th or 6th gear on my Harley Street Glide. All work and are inside normal operating range for the engine, but 4th is in a ready to accelerate state, and 6th is almost coasting.

I won't through in the issue of leaning just yet! (smile)
 
This is interesting. Must have something to do with propeller rpm vs blade pitch vs power needed to pull through the air. For our POH I see three different ways (in the table for 5000msl) to get 148mph TAS. The highest fuel burn uses the highest rpm and lowest MP. (2450@20") The lowest fuel burn is at lower rpm and higher MP (2200@22").

Seems like a classic low gear vs high gear at same speed problem. With the RPM lower and steeper blade angle, a higher MP is needed but is still more efficient over all (like a cruise prop I supposed).
 
Pick the rpm that is the smoothest. Then pick the manifold pressure that gives the fuel burn you want.
 
182T owner here....basically pick what works for you, find the speed you feel like using and go from there, or if you are more concerned about fuel find the fuel you feel like burning!

the poh does provide guidance, a very basic guidance at that, it basically says any power setting in the tables below 80% is acceptable to use. Therefore any of those combinations are acceptable.

I personally fly my plane fast, depending on the altitude over time i have found the MP/RPM combination from the performance tables for those altitudes that work best for me. i typically fly in the 21-22" range and 2300rpm depending on the attitude. The one exception being I found at 6000 my airplane flies great at the 23"/2200rpm. Again I use all values from the POH for the altitude and lean per the POH.

In regards to high controversy about the high temps. In flying the book numbers and book lean to the T. I have no high temp issues. My EGT is typically between 1200-1350, and my CHT's are typically in the 370-380 range.

I have had my bird for over 5 years and my engine is in great shape and no issues (knock on wood)
 
My standard is 2200 RPM/22 INCHES when at cruise altitude, and then I lean to about 1300 EGT. Yesterday I talked with an AP who said keep EGT below 1400 and CHT below 380. My first annual as owner is in December. I expect the engine will be found to be in great shape.
 
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