Manual recommend 5w-30 engine oil. Local Mechanic say use full synthetic oil for better average and long engine life. Pl inform which type of synthetic oil is ok and in which W range it will be ok. Is there is any advantage or any bad effect to engine seals etc. From the previous owner I dont know whichs type he was using. The car Daihatsu Mira 2006 with EF-VE engine which is DVVT Dohc in type. Faizan
You must use the same wight oil. It should still take 5W30.
Synthetic oil will improve gas mileage, power, not noticeably but some and it will deiinately increase the life of the vehicle. However, if you do not keep up pon ALL the manufacturers recommended services, it will not be worth it.
I can't tell you how many motors I have seen blow up from the Anti-Freeze not being changed. You don't have to live in cold area, you must follow all manufacturers specifications to make spending money on synthetic worth it. If you do that, then it is worth it.