Is it true that when we are changing our oil were doing it because of It being Dirty and not because of viscosity breakdown ?

DM

 

Depends on the oil
But ya, for the most part that is the reason. Some have higher volatility which will cause thickening(visc. breakdown) sooner than others. If it's less resistant to thermal and oxidative breakdown, you will get sludge and varnish formation earlier than with others. Then there is the additives, some deplete faster than others.(TBN is big in diesels) Again, depending on the quality of the oil and the amount and quality of the additives used,a ny combination of these can shorten the life of an oil.

All that being said, dirt is usually the first reason. Good filtration can get you more life, but then you have to watch for the other factors to set in.

I know a gentleman who bought an 02 CTD, changed oil(to AMSOIL) at 3000 miles and hasn't changed it since, just filters(has bypass). Does OA every 7500 and currently sits at around 63,000 miiles. Keep it clean and it could last forever

Sorry, got a little winded there:blah:

 

Cool will switch to amsoil

 

I think that now the filtration is good enough that you could run oils for much longer than the recommended interval but the problem is that the additives in the oil get depleted.

 

Agreed.

 

Not only do the additives deteriorate in oils, but the base stocks acidify. As the TBN (total base number) drops (seen on oil analysis reports) your oil shows its age. As long as the TBN number stays within spec and you have good filtration, then you can run longer intervals. Better synthetics, better filtration = longer intervals and better protection.

Nice meeting you in person the other week finally, Heath!

-Chuck

 

Ya, that was funny running into you there. Sounded like you have a pretty mean sounded truck

 

But, is there a way to keep track of these levels as you go, short of sending samples to a lab???