Originally Posted by RayCJ
Here's a couple direct quotes from a Mazda3 owner's manual. Read between the lines and it says, 0w-20 gives better fuel economy and 5w-20 or 5w-30 lubricate the engine better. FWIW, I use the USA recommended viscosity year round.
You came to the conclusion you wanted. The term is confirmation bias I believe.
Here's a couple direct quotes from a Mazda3 owner's manual. Read between the lines and it says, 0w-20 gives better fuel economy and 5w-20 or 5w-30 lubricate the engine better. FWIW, I use the USA recommended viscosity year round.
You came to the conclusion you wanted. The term is confirmation bias I believe.