Does the 1660 have a IH engine (big numbers on the side) or a Cummins? If an IH recommended oil was 30W Cummins-15-40. What is available over there?? Have alot of guys up here in the Northern Plains using Cenex Lubricants. The base oil of hytran is 10w with alot of additives. Guess in your situation stay with hytran instead of something maybe refined locally which might not have everything in it for reliability. Great to hear from someone over there!! In fact from all over, quite a site!