Brother
u r using ZIC A+ (SAE 5W-20, API SN, ILSAC GF-5) That's the highest quality engine oil, Secondly u r using lighter viscosity engine oil its means your car engine 100% OK. When engine consume 1L/1000 KM engine oil then increase oil viscosity like 0W-30. Don't go for any other engine oil.
All engine oil manufacturer companies are going for lighter viscosity like
B4 Now
ZIC A+ (5W-30) 5W-20
Caltex 10W-30 5W-30
Total 5W-40 5W-30
Honda 10W-30 5W-30 etc.....

