A Car's Manual Transmission and RPM/MP Analogy

[Hank]

Just now, Ragsf15e said:

My tpa is 3,000’ so there’s a little of it.  But yeah, I leave wot until it’s time to slow down and enter the pattern.  Does the engine go above 75% power? Sure, but I maintain a safe mixture. 
I don’t think there’s anything wrong with either way, I just wondered if it was something specific to the carburetor engines.  Honestly the best reason I’ve heard for pulling power in descent is to remain in the green arc, but the F has higher limits and if the air is smooth, I’m comfortable in the yellow.

At 500fpm, I generally descend near the top of the green around 165-170 mph (yellow starts at 175). Unless it's really bumpy . . . .

Leaving throttle WOT from takeoff to pattern entry, LOP the whole way, is common with IO engines but nit with the O series due to inefficient fuel atomization and uneven distribution from the carb to all four cylinders.

[carusoam]

Vna and Vne can become a challenge as the MP rises on the descent....

The older birds had lower yellow arcs than the newer ones... fortunately, smooth air is common above 3-5k’ agl....

Mixture just gets leaner as you descend...

When able... descending from further out... it is possible to maintain a higher speed, by lowering the VS.... I used 400fpm...

As the MP builds... so does the speed....

With the O... we have a blue box on the EGT gauge... if you get over worked about keeping the EGTs in the right place... go ROP and put the needle in the blue box....

PP thoughts only, not a CFI...

Best regards,

-a-

[Ibra]

Just to confuse things a bit: my car has constant speed propeller in the front ("cooling fan" doing 3500rpm but not an "air-wheel"), one vintage I flew has WW 1600cc car engine with no gear-box and fixed pitch prop, another new aircraft I fly has engine running at 8000rpm & 1:4 gear-box & variable pitch prop stuck at 1900rpm but no prop control 

The analogy should still work when you start talk about which bit is driving the load the wheel/prop or the engine and rpm regimes