The weight of the oil is the most important. Stuck to 5w30 if that’s what the book says. Your car runs the exact same with both non and full synthetic, only difference if full synthetic doesn’t break down faster and has longer lasting detergents to clean and lubricate your engine for longer and hotter engine temps

I’m no mechanic or dealer tech, but full synthetic oil has a longer usage life in terms of km and wear and tear protection than non synthetic blends. That means you get less km per oil change if you stick to non synthetic. More trips to the dealership for over priced oil changes. Buy your own oil and change it yourself with full synthetic unless the car is still under a maintenance plan and are free