Nissan recommends mineral oil in the owner manual.
This being said, here is why I use 100% synthetic oil instead of mineral oil:
* mineral oil degrades very fast, sometimes as early as 2500 km(viscosity factor).
* mineral oil is subject to very easy contamination when water is present (condensation). A little gas from flooding and it looses all its lubricant properties.
* mineral oil becomes molasse at -30 and the engine head runs dry for quite a while before the temperature raise high enough for normal oil operation. This is a killer for many expensive parts, oil pump, etc...
* A good 100% synthetic (Amsoil, Mobil 1, Bardhal, Red Line, ...) will keep its viscosity and lubricant properties much longer than mineral. Amsoil with any regular oil filter is recommended for 25,000 miles. If you use their special microfilter system (a $500 addon), you can change your oil every 100,000 miles with a yearly oil analysis from their labs.
* Synthetic oils are not degraded by water and they remain liquid even at -40.
But, pay attention to the sticker. Many cheaper syntec are not 100% syntec, as they have a small percentage (+/-5%) petroleum base content. Although these behave better then pure mineral oils in extreme conditions, they offer inferior standards compared with 100% syntec.