So, after a month of not using the car because of horrendous fuel averages and rpm issues, I was finally able to go visit irshad. Who checked the carb and reported everything fine, upon further inspection fuel was leaking out of the carb which was the main cause of the terrible fuel average (we're hoping).
Got the oil changed to 10w30 finally. old oil got changed out at 4500 something kms. It was very dark and black.
Irshad recommended this oil, which I have some reservations against.
I was using ZIC (which one of irshad's guys advised against) API SP fully synthetic. (he said synthetic oils darken earlier on older cars)
However this oil while being 10w30, is mineral (conventional) oil. it is API SN, which is older than api SP (which is the latest) it's ILSAC is GF-5 whereas a newer version; GF-6 was introduced in May of 2018 (6 years ago).
So is this oil worse quality than the previous oil I was using or is it okay to continue to use (and for future oil changes)?