D-Motor advises Synthetic oil in the owners manual : 

   5W40, 5W50, 0W40, 0W50 

• 5 stands for oil viscosity at 0 degrees C
• W stands for Winter
• 40 stands for oil viscosity at 100 degrees C

The LF engine needs an oil that isn’t too watery, but it also needs an oil viscous enough to flow through the engine without causing any problems (without decreasing oil pressure or to overload the oil pump).

Obviously, it depends in the area that you live in. For hot areas (like Africa) the manufacturer recommends a specific oil, if you live in North Canada where it’s cold, the same manufacturer will recommend a different oil.

For extremely cold areas, the perfect oil would be 0W40.

For hot areas, 10W40 is great.

Europe will do with 5 W40/50