2019 KIA Sorento SX - 3.3L GDi V6 - AWD
I would certainly consider it, yes. A 0W motor oil is definitely not needed in a warmer climate like South Florida - especially in summer time. Plus a lower evaporation loss (NOACK Volatility percentage) is certainly desirable (for all the reasons given above).Now you mentioned before that the main reason you use a 0W-XX oil (0W-20 in the winter) is because of the colder temperatures in Northern Ontario (which is perfectly understandable, it gets pretty cold down here in the Southern Ontario as well ).
But if you lived in a much warmer climate, say South Florida for instance, would you still stick with a 0W-XX multigrade or would you consider moving up to a 5W-XX or even a 10W-XX oil (given the lower NOACK numbers of those grades), especially for the hot summer months?
Or is there another reason to stick with a 0W oil?
However, that said, as dubber09 pointed out above, there are many other important factors to consider in a motor oil formulation than just the viscosity and NOACK numbers - such as the base oil composition and the percentage of each base oil used, the additives used in the blend (type, quality, quantity), etc.
The only thing that truly matters however, is the quality and performance of the finished blended product. The point is, a motor oil can’t be judged solely by its base oils – you need to take the entire formulation into account.
Now, as dubber09 noted, a given brand's 0W-xx multi-grade will usually have a higher percentage of lower viscosity Group IV PAOs in the blend than their 5W-xx from the same product line. (Note: PAOs come in different viscosities - some oil formulations use a mix of more than one of them in the blend.) However, that 5W-xx might very well be using a higher percentage of the higher viscosity PAO in its blend. Both could be using the same amount of Group V esters.
(It's important to note that no oil company will voluntarily reveal the exact composition of their oil formulations as that information is proprietary. And no, a simple Oil Analysis will not provide those answers either.)
Now the example I gave above only applies to those Full Synthetic motor oils that actually use PAOs as one of their base oils (a "true" synth oil as dubber called it). But don't assume that all 0W-xx oils use Group IV PAOs as one of their base oils, many don't...
For example, Toyota's branded 0W-20 motor oil (as well as Mazda's and Idemitsu's 0W-20 oils) use only Group III base oils in their blends. Also, the GTL (Gas-to-liquid) base oils that SOPUS (Shell, Pennzoil, Quaker State) uses in most of their high-end products is still classified as a Group III(+) base oil (so again not a "true" synthetic if you go by the original definition of "synthetic") - though I would argue in this case that GTL based oils are very close to Group IV PAOs in actual composition and performance. There are even some 0W-20 oils that are only Synthetic Blends (e.g. Motorcraft 0W-20).
[For more on Base Oil Groups see THIS POST]
Which brings me to another point. In order to pass the "Low-Temperature Cranking" and "Low-Temperature Pumping" tests required to meet the 0W-xx viscosity requirements, a Group II/III based motor oil needs to rely a lot more on Viscosity Modifier polymers (plastics) than an oil based on Group IV (PAOs have naturally high viscosity indexes - although GTL based oils are very close). For instance, Toyota's 0W-20 synthetic oil has a very high viscosity index, but it is loaded with VIIs.
Speaking of VM/VII polymers, a multi-viscosity oil that has a wider viscosity span (the range between the first number and the second number) will need a lot more VII than one with a very narrow viscosity span (and that is true of all brands). For example, a 0W-40 blend will have a lot more VII than a 10W-30 blend (from the same product line). In fact, some 10W-30 oils are basically just straight 30 weights with no VII added at all to the blend.
As to the use of the qualifying words "Full", "True", "Real", "100%", all those words are used pretty much interchangeably today to describe a Synthetic motor oil (as are words like "Ultimate", "Supreme", "Advanced", and the list goes on). They really don't mean much anymore - it's mostly all marketing. Don't count on those labels telling you the type of base oils used in the blend. But as I said above, what really matters in the end is the quality of the finished product.