Which additive in the market works better on automobile engine oil leaks?

The best answer is "none of them". Don't use them! Replace the defective part. The leak sealers work by attacking the seal material, causing it to swell, which temporarily stops the leak. However, the seal materials are then hard and brittle, and over time begin to crack, causing more leaks in new places. Leak sealer works great in the very short term, but causes far more problems later, because you've damaged all the seals, not just the one that was leaking.