Bf 109 G-6 Energy Retention Compared to G-4

[Roland_HUNter]

Hello everyone,

I have been spending some time comparing the Bf 109 G-4 and G-6, and I would like to hear the community's thoughts on their current flight models.

While I fully understand that the G-6 was heavier than the G-4 due to the MG 131 installation and other equipment, the weight difference was relatively small - roughly around 100 kg depending on configuration.

In-game, however, the G-6 appears to lose energy significantly faster in sustained turns than the G-4. The difference feels much larger than what a roughly 3-4% increase in aircraft weight would suggest.

Historically, the G-6 was certainly not considered as agile as the F-4 or G-4, but it also was not regarded as a "brick." Many Luftwaffe pilots continued to use it very successfully, and contemporary accounts generally describe it as somewhat heavier and less harmonious rather than dramatically worse in maneuvering performance.

My question is:

Is there historical documentation supporting the current level of energy loss exhibited by the G-6 compared to the G-4?

Specifically, I am interested in documentation showing that the G-6 should lose substantially more speed during sustained turning maneuvers than the G-4. Based on the relatively small increase in weight and largely unchanged aerodynamic layout, I would expect some degradation in performance, but not the rather pronounced difference currently observed.

I would be very interested in seeing any flight test reports, pilot notes, or engineering data that support the current modeling.

Thank you in advance.

[MDzmitry]

The question is not just having additional weight, but also where this weight is located. G-6 has most of its added weight in the nose, shifting the CoG further ahead. This leads to more stability, but worse responsiveness. And to get it to a similar radius as earlier models, the pilot thus needs to pull on the stick more, causing sub-optimal AoA and more energy bleed. Correct me if I'm wrong, but that's how I see the situation.

Also can't help but note that most your reports, unless noted before by moderation, lack any proper measurements. No track files, no direct comparisons to begin with. Relying on "gut feel" and memoirs will only get you far in casual discussions, but definitely not when trying to convey anything meaningful to the people used to working with hard data and formulas. If you want to vent, feel free, but don't expect a meaningful response to such topics.

As for concrete documentation, bad news: noone was nitpicky enough to count exact differences of turn performance of different models of the same fighter. The only exception on my mind are the British comparing their Spitfire V with and without wing tips. They gave a specific turn difference of some 50 feet of radius at 20000 feet, if memory serves. And even they didn't bother with the energy bleed, most sane people measured turn time, altitude gain, speed and acceleration. Other than that, the best find would be Soviet turn times (they loved measuring these, at least up until the G-2) and occasional turn radius for a random model of some fighter, not necessarily the one needed.

[Roland_HUNter]

18 hours ago, MDzmitry said:

The question is not just having additional weight, but also where this weight is located. G-6 has most of its added weight in the nose, shifting the CoG further ahead. This leads to more stability, but worse responsiveness. And to get it to a similar radius as earlier models, the pilot thus needs to pull on the stick more, causing sub-optimal AoA and more energy bleed. Correct me if I'm wrong, but that's how I see the situation.

Also can't help but note that most your reports, unless noted before by moderation, lack any proper measurements. No track files, no direct comparisons to begin with. Relying on "gut feel" and memoirs will only get you far in casual discussions, but definitely not when trying to convey anything meaningful to the people used to working with hard data and formulas. If you want to vent, feel free, but don't expect a meaningful response to such topics.

As for concrete documentation, bad news: noone was nitpicky enough to count exact differences of turn performance of different models of the same fighter. The only exception on my mind are the British comparing their Spitfire V with and without wing tips. They gave a specific turn difference of some 50 feet of radius at 20000 feet, if memory serves. And even they didn't bother with the energy bleed, most sane people measured turn time, altitude gain, speed and acceleration. Other than that, the best find would be Soviet turn times (they loved measuring these, at least up until the G-2) and occasional turn radius for a random model of some fighter, not necessarily the one needed.

I appreciate the explanation regarding the forward shift in CoG. That is a fair point and certainly more relevant than looking at total weight alone.

My question, however, is not whether the G-6 should be somewhat less responsive than the G-4. I fully agree that it should.

What I am questioning is the magnitude of the difference currently observed in-game.

While we may lack direct G-4 vs G-6 turn performance measurements, we do know that the aircraft were aerodynamically very similar and differed by roughly 100 kg plus the associated CoG shift.

Therefore, I think it is reasonable to ask whether the current gap in energy retention and handling characteristics is proportionate to those changes.

As for measurements, that is a fair criticism. If I revisit the subject in the future, I will try to provide track files and direct comparisons rather than relying solely on subjective impressions.

My intention was not to claim that the flight model is wrong, but rather to discuss whether the observed difference is supported by available evidence.