Originally Posted by Brigadier
You want confusing oil requirements? Buy a Hyundai....
Why is that?
My (and your) 2018 Santa Fe is pretty clear, use any API Service SM *3, ILSAC GF-4 (or above), ACEA A5 (or above) oil.
It gives you a range of viscosities based on temps. 5w-30 or 5w-40 for all temps, 10w-30 for temps that are not below 0°F.
It has similar wording to the Subaru regarding fuel economy vs protection:
Quote
Engine oil viscosity (thickness) has an effect on fuel economy and cold weather operating (engine start and engine oil flowability).
Lower viscosity engine oils can provide better fuel economy and cold weather performance, however, higher viscosity engine oils are required for satisfactory lubrication in hot weather.
Using oils of any viscosity other than those recommended could result in engine damage.
When choosing an oil, consider the range of temperature your vehicle will be operated in before the next oil change.
Proceed to select the recommended oil viscosity from the chart.
The chart does say use 5w-30 for better fuel economy.
My sisters 2010 Santa Fe with the 2.4 says similar, except the viscosities are 5w-20 or 5w-30 for any temp, 10w-30 for above 0°F, and the chart does say use 5w-20 for fuel economy.
I find it pretty simple to choose oil for this.