First of all almost EVERY manufacturer will tell you that the bottom line is: change your oil at least once per year, almost REGARDLESS of mileage. (1500 to 25,000 miles!!)
I think that a ONCE per year oil change is the real kicker ! This is where it becomes a bit dicey. The recommended upper range for the C-5 Corvette Z06 is 15,000 miles. I am told also that 10,000 miles is the other upper range for C-5 Corvettes. The recommended upper range for Amsoil is 25,000 miles. If what I read of Corvette owners posts are any indication, MOST Vette owners DO NOT change their oil in accordance with the DIC.(10,000 to 15,000 miles max.) i.e. they change it FAR earlier, 1500 miles to 5000 miles. LET ALONE go 25,000 miles in a year between oil changes.
For me, I tend to change oil IAW the DIC and that puts it at 13-14.5k miles. This is coincidently app ONCE per year.
So if most "higher" mileage corvettes see 10,000-15,000 miles per year and if "bang for the buck" is a concern, while Amsoil, Redline are great oils, (5.95 and 7.95 per qt respectively) I continue to use Mobil One (3.67 qt)
In the extreme case that you see 25,000 miles per year and want to change oil only once a yr, I without hesitation would switch to Amsoil and or Redline. If you dont, to me the decision is whether that excess marketing hype is worth it.
