20w50 is not sufficient for the modern day engine with intricate oil gaps.Here?s the rule. Oil must fill the space between moving parts yet be able to circulate freely. With smaller, more precise spaces between parts, thinner oils do a better job of flowing freely through the engine while still filling the spaces.
Too thick or too thin oils can both be bad for engines, but damage is neither immediate nor catastrophic; it just reduces overall engine life. Consider that using improper oil could reduce engine life by a conservative ten thousand miles. At a value of fifty cents per driven mile, in a one-hundred-car-fleet, that would be a loss of one million miles for a value loss of five million dollars.
Always use the oil recommended by the engine manufacturer. Believe it or not, you don?t know more about oils than the people who designed and built the engine.
In short 10w50/20w50 is a big no for new gen rolla.20w50 infact is only good for an old engine and aids in reducing smoke/keeps seals/rings intact if the car is running on a thinner viscosity oil.