I noted while re-reading the Concorde's manual that 5w30 engine oil was recommended only for easier cold weather starting and that 10w30 was recommended for average temps above 32F. Given that these recommendations are 10 years old now and that motor oil has advanced in quality...would it be safe to say a 5w30 SM/GF-4 would be acceptable for all-weather use in this engine? Or should I stay with a 10w30 and if yes, for what reasons?
GrtArtiste
I follow the manufacturer's instructions on this engine and use 10W30 most of the year and 5W30 in winter months. It gets very cold (well below 0 F) here so the 5W30 is a good thing to do. I do not use 5W30 in the summer in any of my vehicles since it also gets very hot (above 00 F) in the summer as well. This may cost me a mile per gallon and require I keep two grades of oil in the garage, but the engine will last longer as a result.
Bob
No, it's not. The viscosity of oil and its "quality" are too different things. These numbers have to do with viscosity only (how gooey it is). Stick with the 10W30. The reason is that the 10W viscosity was originally recommended to suit the clearances in the bearings. These clearances are bigger now than they were 10 years ago.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.