I bought Suzuki Cultus 2019 model in January at that time car fuel efficiency was perfect on long route giving 24 Avg and in city 18 to 20. Later on 1st ramzan as scheduled from last owner i changed engine oil filter and etc and moved to suzuki original 10w40 engine oil from that time my car fuel consumption is high last owner was using 0w20 or 5w30 i don't remember. Can i go back to 5w30 sn engine oil 
️ plz answer as soon as possible.
