diff --git a/src/train.h b/src/train.h
--- a/src/train.h
+++ b/src/train.h
@@ -438,11 +438,12 @@ protected: // These functions should not
 
 	/**
 	 * Gets the area used for calculating air drag.
-	 * @return Area of the engine.
+	 * @return Area of the engine in m^2.
 	 */
 	FORCEINLINE byte GetAirDragArea() const
 	{
-		return 120;
+		/* Air drag is higher in tunnels due to the limited cross-section. */
+		return (this->track == TRACK_BIT_WORMHOLE && this->vehstatus & VS_HIDDEN) ? 28 : 14;
 	}
 
 	/**
@@ -465,20 +466,24 @@ protected: // These functions should not
 
 	/**
 	 * Calculates the current speed of this vehicle.
-	 * @return Current speed in mph.
+	 * @return Current speed in km/h-ish.
 	 */
 	FORCEINLINE uint16 GetCurrentSpeed() const
 	{
-		return this->cur_speed * 10 / 16;
+		return this->cur_speed;
 	}
 
 	/**
 	 * Returns the rolling friction coefficient of this vehicle.
-	 * @return Rolling friction coefficient in [1e-3].
+	 * @return Rolling friction coefficient in [1e-4].
 	 */
 	FORCEINLINE uint32 GetRollingFriction() const
 	{
-		return 35;
+		/* Rolling friction for steel on steel is between 0.1% and 0.2%,
+		 * but we use a higher value here to get better game-play results.
+		 * The friction coefficient increases with speed in a way that
+		 * it doubles at 512 km/h, triples at 1024 km/h and so on. */
+		return 30 * (512 + this->GetCurrentSpeed()) / 512;
 	}
 
 	/**
@@ -496,7 +501,7 @@ protected: // These functions should not
 	 */
 	FORCEINLINE uint32 GetSlopeSteepness() const
 	{
-		return 20 * _settings_game.vehicle.train_slope_steepness; // 1% slope * slope steepness
+		return _settings_game.vehicle.train_slope_steepness;
 	}
 
 	/**