I switched over from M1 5W30 to Exxon Superflo 5W30 in my 99 Corolla a couple of months ago.I have used M1 in the motor since I bought it new and it currently has 49k miles.
The M1 usually took 3K miles to start darkening to a light brown color from it's original gold color.
The Exxon Superflo however takes around 600 or so miles to notice a color difference from it's original golden color.By 1500 miles it's dark brown in color.
Does this really mean the Superflo is cleaning better than the M1 ever did or is it oxidizing faster?
The M1 usually took 3K miles to start darkening to a light brown color from it's original gold color.
The Exxon Superflo however takes around 600 or so miles to notice a color difference from it's original golden color.By 1500 miles it's dark brown in color.
Does this really mean the Superflo is cleaning better than the M1 ever did or is it oxidizing faster?