Reasonably treated engines so commonly go over 300,000 and 400,000 miles that I'm not sure it proves much about the oil. For only 3 examples:
My Mazda went over 600K miles on whatever conventional 10W-40 was on sale.
My brother's '85 Jetta went well beyond 300K on the same.
His '95 Avalon is at about 340K on whatever synthetic 5w30 is on sale.
None of those had oil-related wear problems.
My Mazda went over 600K miles on whatever conventional 10W-40 was on sale.
My brother's '85 Jetta went well beyond 300K on the same.
His '95 Avalon is at about 340K on whatever synthetic 5w30 is on sale.
None of those had oil-related wear problems.
Last edited: