My little Toyota has 152K on it, all on 0w-20, and doesn't burn any measurable amount of oil. I only use Mobil 1 or occasionally Pennzoil Platinum, but most 0w-20's are fully synthetic anyway. I average 2MPG above the EPA highway rating, consistently.
Buy a 5w-20 or a 5w-30? Congratulations, you've just bought a jug with a mix of more conventional oil and less synthetic oil than 0w-20.
But hey, if that makes you happy, it really won't hurt your car. And, you'll always find someone to validate your choices, like Merkava.
Or, you could do a UOA and find out the real condition of your engine (suspended metals) and oil (viscosity breakdown), and find out what I did- I could run my 8K, 9K, 10K oil change intervals out even further with no problem.
But if you'd rather remain information-free and make decisions based on hunches, don't let me stop you!