Remove drag physics as that really helps, also disable collisions if there are loads of moving parts as collisions are very laggy

-hollow fueslages lag twice as much as regular fueslages
-physics bodies cause huge amounts of lag (springs , rotators , etc)
-calculateDrag = false on details

reduce the number of separate bodies in your design.

Bodies are a collection of parts connected to a rotator/detacher/winches/etc.
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drag, velocity, rotation, position are all calculated for each Bodies so lots of them can lag your game.
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you can check if you have lots of Bodies in your plane's xml file.. its found at the bottom before the xml values for paint.

also, bombs and missiles add lag when near the ground.

Make things dragless, the less things calculating lag the better

@AircroftDesigin oh you're on tablet ? Dowload more RAM then
(Go on your app store, it's 100% real and efficient !)

@SgtRXMT I'm on a tablet...

@Feanor cheers It worked I'm up to 8 cars now yay

calculateDrag="false" dragScale="0"

@Omel @BuiltBionixInd10 @PointlessWhyshouldi ok then thank you

Drag go bye bye

Decrease the drag maybe.