What kind of oil does the 2014 Infiniti Q50 take?

Depending on Your chosen configuration, Your 2014 INFINITIQ50 will have either a 3.5L V6 engine (VQ35HR), or a slightly larger 3.7L V6 (VQ37VHR). In either case, You'll need to fill it with 5.2 quarts of SAE 5W-30 full synthetic motor oil. If this is not available, You may substitute SAE 5W-40 over the short term, but this isn't recommended if You can avoid it. Oils with higher weights are thicker, which introduces friction into Your engine's normal operation. This will soon lead to premature wear and tear, which in turn leads to Your engine failing sooner than it ought to. Therefore, You should always use the manufacturer's recommended oil with the lowest weight, even though it will cost a few more dollars per change.