<VV> 25,000 mile oil change

[judynrandy at comcast.net]

Hi JR. 
You said our engines are not liquid cooled and run hotter. I say, so what.  260 degrees in a water pumper is still the same as 260 degrees in an air cooled engine.  I can only speak from personal experience.  I've used nothing but Amsoils' 15w40 Heavy Duty Diesel and Marine Oil for the last 30 years.  You asked about shelf life.  I'm not really sure about that.  But what I am sure of is Amsoil has a testimony of a trucker who ran 409,000 miles without an oil change.  He used oil analysis and their by-pass filter.  Amsoil says to change it every 25,000 miles or one year.  Which ever comes first.   Now,  how many years does it take an 18 wheeler to rack up 409,000 miles on the same oil? And, if I remember the testimony the oil wasn't changed because it failed the analysis, the owner traded the truck in!!!!!!!  Obviously Amsoil tells people that to sell more oil. And to cover their warranty issues. (Yes, Amsoil comes with a warranty!!!!) 
      So, I would say if you are worried about leaving your oil in your car for 2 or 3 years, you could just do a $20 oil analysis.  Or just change it, if it makes you feel better.  But why, if it's not necessary.  That thing about changing oil every year is for petroleum based mineral oils.  NOT synthetics.  If it were me, I wouldn't worry about it.   I mean, 409,000 miles on the same oil and your concerned about shelf life? 

Sincerely, 

Randy (Cap'n) Hook 
'63 ragtop 84/pg 
'65 monza 4dr 110/pg