Why shorter OCI with non-synthetic?

[Drew7a]

I have read several comments where members have stated they do not exceed 3-5k with non-synthetics and was curious why?

There are several none synthetics that have a higher TBN then some synthetics and stay in grade, so why change sooner that a non extended drain synthetic?

 

[Malo83]

For the pure joy of draining that nasty oil and filter.

 

[Odd_Ball]

At least one reason is that non-synthetics use more viscosity index improvers (VIIs) which break down with temperature and mechanical shearing.

 

[CentAmDL650]

Convention base oil oxidises & nitrates faster than synthetic with the same amount of combustion blowby. Meaning by 3 - 5k mi it likely contains the precursors to varnish and sludge that detergents and dispersants may not be able to prevent from depositing. That's why the earlier oil change makes sense.

 

[GMAX]

Oh my, I guess one excuse is as good as another when it comes to the need to change oil.

 

[ad244]

I have read several comments where members have stated they do not exceed 3-5k with non-synthetics and was curious why?

There are several none synthetics that have a higher TBN then some synthetics and stay in grade, so why change sooner that a non extended drain synthetic?

By this logic, Diesel oil (very high TBN) should last the longest!

 

[RDY4WAR]

The TBN is only one factor. What you really need to look at is oxidation.

Conventional base oils lack the oxidation resistance of synthetic base oils, and no amount of detergents and dispersants can make up the difference. Heat will oxidize the conventional base oils long before the DI pack is wiped out.