An overview of War Thunder’s Manual Engine Control (MEC) — what each function does, and how to get the best out of your plane’s piston engine
Manual Engine Control (MEC) is a set of keybinds available in War Thunder’s realistic control settings. These keybinds allow you to control parameters of the engine system that are normally controlled automatically by the “Instructor” when using mouse-aim. These parameters include:
- Radiator settings
- Propeller pitch
- Supercharger gear
- Fuel mixture regulation
Listed roughly in order of how much these settings would be used from battle to battle, these controls can help you ease the stock grind on your prop plane, and gain maximum control over the plane’s flight characteristics. Such an advantage can be crucial in Air Realistic and Simulator battles.
To enable the use of MEC, you must navigate through your War Thunder options:
- Access the drop down menu on the upper left of the hangar screen
- Select ‘Controls’
- Enable “Full-Real Control” – this is just to reveal all Engine controls, once you set keybinds for each individual engine control you can change back to Mouse aim (or any control method you prefer).
- Scroll all the way down, and you will see the full list of available engine controls
Bind the keys as you wish, or you can copy my MEC setup. Either way, once you have bound your keys to the functions above, you can select your preferred control method (such as Mouse aim) and these keybinds you have selected will still work.
Now that you have all necessary controls bound, its now time to describe what each function does. To find optimal settings for a specific plane, check this spreadsheet.
Engine controls mode
This is simply the keybind that allows you switch between automatic engine controls (default) and MEC. In combat, it can be hard to focus on babying your engine, so usually, MEC is used during the initial climb or while cruising out of combat.
The mixture setting manages air/fuel mixture by controlling how much fuel is allowed in the engine’s combustion chamber. Air fuel ratios are listed in %, and at low altitudes default at 60% (60/40 fuel/air mix). As you climb to higher altitudes, the air gets thinner, and to compensate, the fuel mixture has to be reduced to keep the mix balanced. However, too little fuel relative to air density causes the engine to lose power, as there isn’t enough energy being released from combusted fuel to drive the engine. On the other hand, too much fuel can flood the engine, as there isn’t enough air to combust the fuel, causing a drop in power output. The optimal fuel mixture depends on each plane and its engine, but for most planes, it is best to remain at about 60%.
The propeller pitch dictates the angle of the propeller relative to the direction of travel of the aircraft. Changing the propeller pitch affects your aircraft’s drag, as each propeller blade acts as a wing pushing through the air. As the aircraft moves forward, so does the propeller, giving the blades both a rotational and linear movement, like drilling a screw into wood. A fine pitch is optimal for full thrust (100% pitch in-game), useful in combat and climbing. A moderate pitch (50% to <100%) is useful for reducing drag and strain on the engine, such as when cruising to keep engine temperatures low, as the engine does not have to run at high RPM. Coarse pitch (0%) is only useful to fully minimize drag when gliding back to base, as it produces little thrust.
In game, prop-pitch % change the angle of the propeller blades within operational limits set by the engineers who built the plane. 90-100% pitch is the normal range to use for climbing and combat. In automatic control, the propeller pitch is dictated by your throttle, providing 100% pitch at full thrust/WEP, feathering the pitch as you lower throttle. Using MEC, 100% prop pitch can be combined with 0% throttle, which allows your airplane to greatly slow down, making it easier to descend from altitude when landing in a bomber, or, alternatively, allowing you to perform the Bf-109 “airbrake”.
However, if your plane is travelling at too great of a speed, and your prop pitch is high, there is a risk of exceeding the engine’s maximum RPM and breaking the motor. Its pretty unlikely, but its possible. At most, you will usually get the RPM warning before getting high enough RPM to actually blow the motor.
Auto-prop pitch is a function certain later piston engine aircraft come with, that automatically create optimal thrust-drag depending on flight conditions. Its useful to keep that on unless your engine is dead and you need to glide home.
Propeller aircraft come with two sets of radiators – a standard radiator, which can cool the motor (radial engine) or cool the liquid coolant (inline engine); and an oil radiator, which cools the motor oil. After the propeller, the radiator is the second source of drag you can control. In most situations, your radiators will be partially or fully opened to allow the engine to cool, after all, an overheated engine is a dead engine. Without MEC, the radiators will react to the engine temperature, and allow your plane to run hot before opening them. Without MEC, the radiators will also close automatically (partially or fully) when using WEP. With MEC, you can fully open radiators while WEPing, and keep your radiators open before you overheat. In certain aircraft, such as the P-47D-28 and F4U-4B fighters, you can keep certain radiators fully open for your entire flight, as their design vastly minimizes drag even when opened. Radiator control is more important in maintaining maximum climb rate than it is in combat, so once you are done climbing it is best to set the radiators to a balanced cooling/drag setting or simply enable automatic radiator control if the airplane is equipped with it.
The supercharger is an air intake designed to compress and force air into the engine. Turbosuperchargers as they were called back then could compress air using engine power (supercharger) or using a fan spun by exhaust gases (turbocharger). The compressed air generates boost pressure, and a greater boost pressure means more air in the engine, in turn allowing for more gas to be burned, producing a higher power output. In addition, compressing the air allows the engine to maintain peak power output at higher altitudes. Early pre-war piston engined aircraft often lacked any turbosuperchargers.
Among WW2 aircraft, the most common turbosupercharger design was the mechanical supercharger. Superchargers are mechanically driven by the engine’s power, meaning the engine gives some of its power to spin the air compressor in exchange for the supercharger’s boost pressure, providing a net gain in power overall. This net gain of power isn’t always guaranteed however, as at too high an altitude, the supercharger may lose effectiveness, not being able to output enough pressure.
To allow a supercharger to be effective at higher altitude, the supercharger can be geared, allowing a gear reduction between the engine and supercharger to drive the air compressor harder at higher altitude, generating more pressure, and thus boost. Engaging high supercharger gear at low altitude however can be less beneficial compared to low gear, as the high gear demands more engine power to spin the compressor than low gear. Most aircraft have a single speed supercharger, however some had a two-speed, while few have a three-speed (ie Ta-152 H-1, J2M series). Different aircraft have different altitudes at which it is optimal to shift to the next supercharger gear.
Magnetos control which spark plugs fire in the engine (as each cylinder in an aero engine has two spark plugs). This setting is pretty useless in War Thunder, and can be ignored.
As stated before, prop pitch affects propeller angle within a set range. Prop feathering allows you to exceed that range, either fully minimizing drag for gliding when lowered to minimum, or more easily breaking your motor at maximum setting. Use sparingly, and carefully.
As already outlined in the Functions section, usage of various MEC controls can provide various benefits depending on airplane conditions and engine performance. This is essentially a tl;dr of the previous section.
- Engine controls mode – toggles between default automatic control and MEC
- Mixture – sets fuel % in engine combustion mixture. Settings depend primarily on altitude, higher altitude = lesser fuel % in mixture.
- Propeller pitch – sets prop angle relative to airplane travel axis within set bounds that still produce usable thrust. Less % = less thrust, less drag, engine runs at lower RPM. More % = greater thrust, more drag, engine runs at higher RPM. High % is most useful for take-off and combat, Low % is useful for cruising and descent for landing.
- Radiator – sets radiator flap openings. Greater % = more cooling, more drag. Lesser % = less cooling, less drag. Depending on radiator design, some radiators have slim to no effect on drag and can be left fully open.
- Supercharger – sets supercharger gearing. Not all aircraft have a geared supercharger (or a supercharger at all). Low gear is optimal for low altitudes, as it saps less power from the engine, while High gear is for high altitudes, as it compresses air at a greater pressure. In certain aircraft, such as the F4U-4, WEP’s power boost is affected by both altitude and supercharger gear. At a certain medium altitude before engaging SC gear 2, WEP is ineffective.
- Magneto position – useless for War Thunder
- Propeller feathering – sets prop angle beyond prop pitch parameters. Can possibly lead to loss of thrust or high RPM engine damage. The main usage is to allow minimum drag for gliding at 0%.
War Thunder Real-Time Information
War Thunder Real-Time Information is a separate program that accesses game server data to provide more detailed output on your plane’s current condition. It can monitor all engine settings (such as those affected by MEC), as well as general aircraft settings such as pitch angle, angle of attack, angle of slip, climb rate in m/s, horsepower output, and thrust force output. It is quite useful for knowing specific information the game does not provide, and is a completely legitimate modification to the game, as it only displays information, it does not modify it.
The latest release can be downloaded here.