guys i changed engine oil to Total quartz at 15k, at that time my fuel avg 12.7 and now i am at 20k and my fuel avg has dropped to 12.2? why is that? before that i used Suzuki's own oil at 5k and 10k (10w-40) and fuel avg actually kept increasing slowly and gradually....
Anyone has any idea why this my fuel avg dropped when i changed oil to Total Quartz (5w-30) fully synthetic? Now what shall i do at 20k?
which oil shall i use this time and shall i also change the grade?