My 2010 Jeep Wrangler Owners Manual recommends 5W20 oil, no options for up or down a grade based on temperature or driving conditions.
What is the truth? Does this cause extra wear on engine components, just to get slightly better mileage? Is it better for the engine to run 10W30 in western Washington where the temp never drops below 0F or rarely climbs above 100F? Did Jeep actually redesign the engines to work with the lighter oil? What are the facts?
In gas-powered engines, Amsoil 5W20 oil is recommended for 10,000-mile or 6-month intervals or longer where stated by the vehicle's manufacturer or indicated by the vehicle's oil life monitoring system. Change the aftermarket, OEM or Amsoil oil filter with the oil at every oil change.
Answer: 5w20 oil has less film and shear strength than a 5w30, 10w30 or a 0w30 motor oil. This can lead to increased engine wear under today's demanding heat and high-stress engine performance conditions.