Question about rubber wheels from 2006

I recently got 7898 Deluxe Cargo Train used, and the motor works very well, but the engine can barely pull more than 2 cars. The wheels keep slipping, and when the train stops it slides a few inches. The wheels have black rubber inserts instead of the clear rubber inserts we have today. They don't have nearly as much grip, and they feel a bit dried out. But were they always like that, or has the rubber just aged badly? If I bought new wheels on Bricklink, would they still have the same...