You will see fuel economy benefits of 0W-20 if you do lots of short trips. If you mostly drive on highways or motorways, then not much difference between 0W-20 and 5W-30. In this case, 5W-30 could be a better choice because you will save some money on the oil cost as well.
Just to give you an idea how out of spec 10W-40 is for Alto, Suzuki Japan recommends 0W-20 for NA R06A engine and 5W-30 for turbo variant of the same engine. Turbo engines produce massive heat and even then, they are recommending 5W-30, not 10W-40. Pak Suzuki is the only Suzuki's local partner who recommends such nonsense oils for modern engines. Compare the oil viscosity recommended by Maruti Suzuki for its different models.