About oil change once a year

[Garak]

Personally, if I were to store a vehicle for an extended period, I'd prefer to change before storing it. That being said, if an engine were halfway along a severe service interval, I wouldn't be in a rush to change the oil if it were going to be sitting for a few months, either.

If I've got a thousand miles on the oil before a few months of storage, no big deal. If I'm 100 miles from an oil change and it's going away for a year, I'm not waiting to squeeze the extra 100 miles out.

 

[Linctex]

Originally Posted by Ducked
Originally Posted by Linctex
Originally Posted by Vlad_the_Russian
So this is a bit extreme, but... here is what happens to oil when it sits in the engine for too long, regardless of miles. Steady diet of Castrol Edge, but for 5+ years engine was just sitting. Engine is in good condition, for a 1990s BMW at least. But oil pan and oil filter cup are filled with this gunk because the oil was just sitting there, and over time oil lost its properties.


I think that car has had some serious short tripping done.

Only condensation present in the oil will cause that. Period.



Such certainty? I'd say this is unknowable, but, as I originally suggested, glycol contamination from a coolant leak might also do it, and in this case seems more likely.


My reply was worded poorly....
I wasn't trying to exclude glycol contamination, and that is also a VERY likely cause to this sludge occurring

 

[chims]

Originally Posted by Boomerang

Most synthetic oils wants to change once a year, even though the miles are not that much. Any reason? Is it because of the condensation issue? For eg: Amosil XL wants to change it at 6 months/10k miles.


Recommended oil change intervals vary by vehicle manufacturer. But to answer your question, they do it once a year to regularly inspect what's under the hood. So, it is really for the purpose of preventive maintenance. Better safe than sorry, right?

 

[willbur]

How do we know this was not present before it sat for 5 years?