<VV> 25,000 mile oil change

[Chris & Bill Strickland]

>That thing about changing oil every year is for petroleum based mineral 
>oils. NOT synthetics. 
>

We change engine oil, not because the lubricant wears out, but because 
it gets contaminated, and these days that may include becoming 
contaminated with ethanol, and where there's ethanol, there's water.  
And a stock Corvair does not have an ideal PVC system.

Engines diesigned and built for the sixties don't magically quit 
contaminating the oil just because you change to a synthetic oil. Yes, 
it may reduce wear on critical engine parts, reducing the contamination, 
but not eliminating it.  Even Mobil 1, which used to claim extended oil 
change intervals of I believe 50,000 miles dropped that claim some time ago.

Bill Strickland