When considering the maintenance of a high mileage engine, one might ponder the potential benefits and drawbacks of utilizing thicker oil. Is it possible that opting for a more viscous lubricant could safeguard against the wear and tear associated with extended use? In high mileage scenarios, where engines often experience increased clearance between components due to wear, would a thicker oil offer improved protection by maintaining a more robust film strength? Conversely, could the introduction of a higher viscosity oil inadvertently lead to compromised performance, diminished fuel efficiency, or even elevated oil pressure that strains aging seals? Furthermore, what implications might this choice have on engine cleanliness and sludge buildup? As the engine ages, how crucial is the balance between reducing friction and ensuring proper flow rates? Could the characteristics of the thicker oil potentially exacerbate issues like leaks or, on the contrary, alleviate them? These questions merit careful deliberation and analysis.