Hi, I purchased my red color Appache rtr 160 bike 1year ago .Usally like all other riders I used the castrol engine oil everytime to my bike but it is not satisfied with the performance of my bike one of my bike mechanic suggested me the engine oil name TRU4 synthetic oil its cool to use it as it is manufactured by the same company(TVS) .The main feature I like is Synthetic oil flows better in cold conditions it priced like around 525/- liter .Friends you can give a try.