The 109... questions

[Blackdog_kt]

Originally Posted by adonys

it's the same thing I said. I was writing from memory (haven't checked exactly in the game), yet I've said throttle back and low RPM (around 2000, but actually going down towards 1800), if the high prop pitch rises the RPM, then you'll lower it until you get around the needed RPM.

Which is the RPM you're using for cruising, isn't something between 1800-2000?

The two important causes for fuel consumption are throttle RPM and fuel pressure. I said throttle RPM, because RPM going higher because of the wind forcing a faster rotation of the propeller shouldn't accelerate your fuel consumption. using the same car analogy, if you let it loose downhill, faster rotation of wheels because of the gravity won't make you consume more fuel to acquire it.

That's what I believe, I'm also no pilot, just using logic and knowledge. So, don't worry, I don't have any problem arguing or being corrected (I'm not stupid enough to think I'm always right, I'm not God), on contrary, these kind of discussions improves the knowledge of all of us, and that's a good thing, isn't it?

That's a good point you're raising there, if the engine "rolling downhill" consumes as much fuel as when it's working normally at the same RPM, to which i don't know the answer

In cruise i use the values stated in the PDF manual for CoD (1.2 Ata and approximately 2300RPM) and this easily gets me 390km/h IAS at low altitudes (2km or so).

There are also different kinds of cruise and we don't know which one the manual gives. Endurance cruise gives the most amount of flight time per liter of fuel.
Economy cruise is different and gives the biggest amount of distance traveled per liter of fuel.

Assuming i'm flying a cessna, let's say it has an economy cruise of 25 inches Hg manifold pressure and 2500 RPM and an endurance cruise of 20 in Hg and 2200 RPM:
If i use 25"/2500 RPM, my fuel will last a shorter amount of time but in that time i will have traveled a bigger distance.
If i use 20"/2200 RPM, my fuel will last longer but the total distance travelled will be less.

Applying this to the 109, i suppose the values states in the manual give the best range and not the best endurance/loiter time. This is a pure guess on my part, i'm just guessing that a sleek fighter will have a relatively high economy cruise speed and since i'm getting almost 400km/h it seems reasonable.

If we wanted to maximize time over London we would combine both, economy cruise to the target area, endurance cruise while patrolling and economy cruise back to base

[adonys]

The cruise I've posted up in there was done at lower RPMs than the one in manual/yours (1800-2000 compared with 2300), and it is exactly for the lowest consumption of fuel/distance covered, therefore should be an economy cruise, not a fast (as I believe the one from manual to be, at 2300 RPM you're almost in the full power 2500 RPM area) or an endurance cruise (maximize the time staying in the air).

PS: yet, using the manual 2300 RPM for cruising.. isn't as being a lower RPM compared with my 2000(1800) one, as you said when we've started this discussion.. as it is actually a higher RPM, isn't it?

[Blackdog_kt]

Of course. I just went by the assumption that the manual states maximum range cruise. Maybe it's fast cruise and yours is more economical, i will probably try out your settings during the weekend

[Hellbender]

Question: So far the Fuel mixture in the 109 could be set by me only @ 0 % or 100%. At high altitude, I see smoke coming out of the Exhaust which vanishs by using Mixture 0% which is giving me almost no engine power.
In british planes I can set up the fuel mixture from 0-100% , but i only got 2 extremes on the 109.

[JG52Uther]

I think mixture in the 109 is bugged at higher altitudes.

[robtek]

afaik there is NO mixture adjustment for the 109!
Always "auto-rich"

[adonys]

yeah, the mixture of 109 is auto, you shouldn't fumble with it.