How much liters of oil come into the V50 1.6 gasoline?

Hello, I just had the V50 1.6 gasoline 101 hp year 07/2005 when changing oil. Before I had traded down the Volvo dealer, because 25 EUR / liter for an oil which costs me online about 10. EUR was a bit much to me. I was surprised then that the Castrol 0w-30 SLX only 4 liters were filled. So it is also in the instruction, however, during the last inspections more has been tipped in. In the service booklet it is true that a new car gets at first more oil – however, the oil quantity of 5.2 liters over 4.8 liters has been reduced to now 4 liters. The car has now 43,000 km and today its total 4th oil change. Normally you only need every 20,000 km – but rather an oil change too much than too little 🙂 Is this reduction normal? I wanted to look at the oil rod – but was too dark. Thanks & Gruss E.