i have liana 220k on odo recently replaced a kabli ,engine car drive is improved after engine change but horrible has become more than horrible it gives 5kmpl within city the oil i am using is 10w-40 shell hx5
on highways its a different story it gives around 10-13 kmpl with ac max which is also less
the engine i replaced is same m13a ,fuel injectors never got services since long time how can i get them service & what other things to improve mileage also do i need to fix cat converter & how can i get them cleaned & most importantly mileage regards.