Salam.
I have Ek wagon 14/17, almost 100k driven. Last week I changed the engine oil as it was due. I was using Zic 10W40 for one year, but this time I switched to Shell 10W40. Before the oil change, I was getting a mileage of around 14 to 15km/l in the city without AC. Soon after the oil changed, it dropped to 10. Also, the engine sound has increased and I feel k gare bhari hogaye ha....
Does oil affect the mileage of the car?
Experts, please advise