diff --git a/ROMFS/px4fmu_common/init.d-posix/px4-rc.gzsim b/ROMFS/px4fmu_common/init.d-posix/px4-rc.gzsim
index 5b4676e60e5..c5003d6db11 100644
--- a/ROMFS/px4fmu_common/init.d-posix/px4-rc.gzsim
+++ b/ROMFS/px4fmu_common/init.d-posix/px4-rc.gzsim
@@ -64,8 +64,13 @@ else
 	echo "INFO  [init] Standalone PX4 launch, waiting for Gazebo"
 fi
 
-# Wait for Gazebo world to be ready before proceeding
+# Wait for Gazebo world to be ready before proceeding.
+# In standalone mode the world name is not known yet, so discover it from the running gz instance via the clock topic
 check_scene_info() {
+	if [ -z "${PX4_GZ_WORLD}" ]; then
+		PX4_GZ_WORLD=$( ${gz_command} topic -l 2>/dev/null | grep -m 1 -e "^/world/.*/clock" | sed 's/\/world\///g; s/\/clock//g' )
+		[ -z "${PX4_GZ_WORLD}" ] && return 1
+	fi
 	SERVICE_INFO=$(${gz_command} service -i --service "/world/${PX4_GZ_WORLD}/scene/info" 2>&1)
 	if echo "$SERVICE_INFO" | grep -q "Service providers"; then
 		return 0
@@ -150,12 +155,35 @@ if [ -n "${PX4_SIM_MODEL#*gz_}" ] && [ -z "${PX4_GZ_MODEL_NAME}" ]; then
 		exit 1
 	fi
 
-	# Set physics parameters for faster-than-realtime simulation if needed
+	# Set physics parameters for faster-than-realtime or slower-than-realtime simulation if needed.
 	if [ -n "${PX4_SIM_SPEED_FACTOR}" ]; then
 		echo "INFO  [init] Setting simulation speed factor: ${PX4_SIM_SPEED_FACTOR}"
+
+		WORLD_SDF="${PX4_GZ_WORLDS}/${PX4_GZ_WORLD}.sdf"
+		if [ -f "${WORLD_SDF}" ]; then
+			sdf_gravity=$(grep -m1 '<gravity>' "${WORLD_SDF}" 2>/dev/null \
+				| sed -e 's|.*<gravity>||' -e 's|</gravity>.*||')
+			if [ -n "${sdf_gravity}" ]; then
+				GZ_GRAVITY_X=$(echo "${sdf_gravity}" | awk '{print $1}')
+				GZ_GRAVITY_Y=$(echo "${sdf_gravity}" | awk '{print $2}')
+				GZ_GRAVITY_Z=$(echo "${sdf_gravity}" | awk '{print $3}')
+			fi
+			MAX_STEP_SIZE=$(grep -m1 '<max_step_size>' "${WORLD_SDF}" 2>/dev/null \
+				| sed -e 's|.*<max_step_size>||' -e 's|</max_step_size>.*||')
+		fi
+
+		# Fall back to defaults. These are wrong for custom-gravity worlds and are only used when the
+		# world SDF cannot be located (e.g. standalone launch with PX4_GZ_WORLDS unset).
+		GZ_GRAVITY_X=${GZ_GRAVITY_X:-0}
+		GZ_GRAVITY_Y=${GZ_GRAVITY_Y:-0}
+		GZ_GRAVITY_Z=${GZ_GRAVITY_Z:--9.80665}
+		MAX_STEP_SIZE=${MAX_STEP_SIZE:-0.004}
+
+		echo "INFO  [init] Preserving physics: gravity=(${GZ_GRAVITY_X}, ${GZ_GRAVITY_Y}, ${GZ_GRAVITY_Z}), max_step_size=${MAX_STEP_SIZE}"
+
 		${gz_command} service -s "/world/${PX4_GZ_WORLD}/set_physics" --reqtype gz.msgs.Physics \
 					--reptype gz.msgs.Boolean --timeout 5000 \
-					--req "real_time_factor: ${PX4_SIM_SPEED_FACTOR}" > /dev/null 2>&1
+					--req "real_time_factor: ${PX4_SIM_SPEED_FACTOR}, max_step_size: ${MAX_STEP_SIZE}, gravity: {x: ${GZ_GRAVITY_X}, y: ${GZ_GRAVITY_Y}, z: ${GZ_GRAVITY_Z}}" > /dev/null 2>&1
 	fi
 
 	# Set up camera to follow the model if requested