The note might interest you
FYI. The reference to using anything other than the prescribed viscosity does not appear in my 2019 U.S. Owners Manual (duplicate language for 3.6 engine deleted):
Engine Oil — Gas Engine Change Engine Oil The oil change indicator system will remind you that it is time to take your vehicle in for scheduled maintenance. Refer to the “Maintenance Plan” for further information.
NOTE: Under no circumstances should oil change intervals exceed 10,000 miles (16,000 km), twelve months, or 350 hours of engine run time, whichever comes first. The 350 hours of engine run or idle time is generally only a concern for fleet customers.
Gasoline Engine Oil Selection For best performance and maximum protection under all types of operating conditions, the manufacturer only recommends engine oils that are API Certified and meet the requirements of FCA Material Standard MS-6395. American Petroleum Institute (API) Engine Oil Identification Symbol This symbol means that the oil has been certified by the American Petroleum Institute (API).
The manufacturer only recommends API Certified engine oils. This symbol certifies 0W-20, 5W-20, 0W-30, 5W-30 and 10W-30 engine oils.
CAUTION! Do not use chemical flushes in your engine oil as the chemicals can damage your engine. Such damage is not covered by the New Vehicle Limited Warranty.
Engine Oil Viscosity (SAE Grade) — 5.7L Engine Mopar SAE 5W-20 engine oil approved to FCA Material Standard MS-6395 such as Pennzoil, Shell Helix or equivalent is recommended for all operating temperatures. This engine oil improves low temperature starting and vehicle fuel economy. The engine oil filler cap also shows the recommended engine oil viscosity for your engine. For information on engine oil filler cap location, refer to the “Engine Compartment” illustration in this section.
Lubricants which do not have both the engine oil certification mark and the correct SAE viscosity grade number should not be used. [emphasis mine]
Synthetic Engine Oils You may use synthetic engine oils provided the recommended oil quality requirements are met, and the recommended maintenance intervals for oil and filter changes are followed. Synthetic engine oils which do not have both the engine oil certification mark and the correct SAE viscosity grade number should not be used.
Materials Added To Engine Oil
The manufacturer strongly recommends against the addition of any additives (other than leak detection dyes) to the engine oil. Engine oil is an engineered product and its performance may be impaired by supplemental additives.
Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 82393 miles