Most of the time, car manufacturer do not know what condition are you facing at site. The manufacturer recommendation should be taken as a guide , not a must follow advice. Generally, newer car with closer gap tolerance between cylinder wall and piston uses a thinner lube oil...while older cars with wider gap tolerance uses a thicker oil to compensate the sealing.
Between mineral oil and synthetic oil, my preference is mineral oil. Though synthetic oil have the durability over the mineral oil, one should also take consideration of the airborne silica sand(silica is the most abundant material in our soil) pick up while driving on the road ... often these airborne silica are so tiny micron in size that they passes through the air filter. Silica particle are hard and can cause abrasion in metal moving parts. Imagine you have a synthetic oil that you drive for 10,000km ... you would have accumulated much airborne silica particle in the system than a mineral oil that requires you to drive only 5,000km.
Frequent oil change = frequent contaminant removal = lesser abrasion wear to your engine system.
