I solved it. It has to do with the size of the landscape quads. I guess there’s some sort of instability with collision with many quads at once. My vehicles in my game work 100x better now that I’ve scaled up the landscape to where the quads are bigger than the area that the tire contacts the ground. Try making a landscape of scale 100 to 300, where the quads are about 50-100 unreal units across. You may have much better luck.