pag gas engine kasi hindi masyado need na robust ang oil to used.. a good semi synthetic will do, but if you're after longevity and maximum performance try to use an oil with CI-4 rating together with an SL API rating...

Good amount of Phosphorus/calcium/moly/boron and a very good TBN reserve..

traditional gas engine oil (SM/SN) will only have 6-8 TBN rating whereas CI-4 with SL rating will have TBN of 9-10...