2016 Infiniti Q70s Oil Type Viscosity

[lyrix]

Hello,

I just want to know the appropriate oil type to use on my 2016 Infiniti Q70s Model. The dealership uses Nissan’s 5w30 Fully Synthetic oil, but the ambient temperature in Kuwait in Summer reaches 55 Degrees Celsius. I spoke with the dealership regarding the viscosity chart but they avoided such chart and just told me we use 5w30 on all Infiniti cars worldwide. Here is where I believe the mechanics in the dealership and people responsible there are absolutely wrong.
Every dealership should use the oil types that meet the standards of the Country the car is in. So let’s say I live in Russia where the weather is mostly cold. I would use 10w15 for example. In Kuwait as I mentioned, it reaches 55 Degrees so I’d use 5w50 for example. ( This is what I’m using ) When I explained this to the dealership they told me we cannot supply anyone with 5w50 and if you want to use that type of oil then you should buy the oil filter and have the oil changed outside the dealership as we will not take responsibility on oil changes that are not from the dealership nor will we use any customer’s own oil if they buy it from somewhere else. It’s like they only want me to use 5w30 when logically and scientifically they are wrong to do so. Now I need clarity on this subject and what do you think? Who is right and who is wrong here? Not to mention, I even contacted Infiniti’s Headquarters and they actually said the same thing, “We use 5w30 on all Infiniti Models.” Please I need a definitive answer to this, am I missing something with my experience and studies or is Infiniti just trying to get the cars spoiled so that we pay $$$$$$ for fixing later?

[VStar650CL]

The first number is cold flow, so in Russia you'd want a 0w and not a 10w. With full synthetic oils viscosity isn't nearly as important as it was with old school refined oils, except to the extent that you still need enough cold flow and surface tension to protect the engine before it's warm and enough warm flow that the VVT's work right and don't throw codes. Once at working temperatures, the enormous film strength and breakdown resistance of full synthetics make the viscosity almost irrelevant. Frankly, IMHO, you're worrying about nothing.