(svn r21712) -Change: Tune 'realistic' acceleration even more to make more trains reach their top speed.

src/ground_vehicle.cpp

@@ -127,7 +127,7 @@ int GroundVehicle<T, Type>::GetAcceleration() const
 	}
 	/* Air drag; the air drag coefficient is in an arbitrary NewGRF-unit,
 	 * so we need some magic conversion factor. */
-	resistance += (area * this->gcache.cached_air_drag * speed * speed) / 500;
+	resistance += (area * this->gcache.cached_air_drag * speed * speed) / 1000;
 
 	resistance += this->GetSlopeResistance();
 
@@ -151,7 +151,8 @@ int GroundVehicle<T, Type>::GetAcceleration() const
 	}
 
 	if (mode == AS_ACCEL) {
-		return (force - resistance) / (mass * 2);
+		/* Divide by 4 to compensate for the wacky game scale. */
+		return (force - resistance) / (mass * 4);
 	} else {
 		return min(-force - resistance, -10000) / mass;
 	}

src/train.h

@@ -462,11 +462,10 @@ protected: // These functions should not be called outside acceleration code.
 	 */
 	FORCEINLINE uint32 GetRollingFriction() const
 	{
-		/* Rolling friction for steel on steel is between 0.1% and 0.2%,
+		/* 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;
+		return 15 * (512 + this->GetCurrentSpeed()) / 512;
 	}
 
 	/**