@ topic
Altis auto has no problem on CNG whatsoever...
Someone told me that advancer deteriorates car'z performance if car already has an advancer i.e VVTI and IVTEC. So I got the advancer removed from my Vitz and guess what!!! its pick improved... A few frnds copied me and the result was mixed i.e favorable iun cases and unfavorable in others...
However, the concept still sounds logical... Built in advancer is always better than advancer that comes with CNG kit...