@Arezfei you should really try the ceretac.. pour in my new bmw previously got this diesel very harsh sound can even hear from cabin..after 1 day of pour in..it works like magic! now i barely even hear the engine even if im standing outside near the car..
for the oil yes ive tried on 2000 waja and 2000 iswara..but i did the lambda flush before head..i cant comment on waja brother's car but i didnt drove for 1 time 50% smoother in term of gliding the car..but for iswara now the car glide even faster and very ringan..
you should try its worth your money for that price
review on liqui moly engine oil