> I have 16 quarts fo Penzoil full synthetic ATF. My 1977 C-6 says to use type F. What happens if I use it anyway? (comple

I have 16 quarts fo Penzoil full synthetic ATF. My 1977 C-6 says to use type F. What happens if I use it anyway? (comple

Posted at: 2015-01-07 
Don't do it. Type F has completely different friction modifiers. Using a non-F will totally change the shift feel and may burn the clutches. If you value this vehicle, then use the correct fluid. It's that simple.

Generally speaking, I agree with you. There have been some improvements in the last 37 years and I was hoping that the new synthetic would be compatible. Maybe not.

a

Always use what the manufacturer recommends.