So much bad info in this thread. There are no mechanical differences from one country to the next and a 0w-20 is not required.....anywhere. It is recommended, and legally, recommended, is completely different than required. In America the only legal requirement is that the oil display the ILSAC starburst symbol for gas engines. Additionally there is a minimum and maximum oil pressure required at idle and then at 3,500 rpm. If your oil meets those parameters it is permited. The acceptable oil pressure range, especially at 3,500 rpm is huge which allows us to use a wide range of viscosities. If engine wear and tolerances were the sole dictator of viscosity we would not see 0w-40 for example being allowed in the Middle East (a hot market) but 0w-20 being "required" in hot Texas. 0w-20 is recommended solely for emissions and mpg and not required. If anyone questions this I will provide you with an image from the owners manual and factory repair manual proving as such.
Long story short - this engine (and oil pump, tolerances etc etc etc) is designed to use just about any viscosity readily available.