Add packs and oci synthetic vs conventional

[rjacket]

If add packs getting depleted are the reason to change oil, then, all things being equal, why wouldn't a conventional with the equivalent add pack to a synthetic, not go just as long?

Why can't you put a superior add pack (eg same as the one that goes into a synthetic) into a conventional and call it EP?

 

[river_rat]

Shear maybe? I dunno. Maybe you could.

 

[SLCraig]

Some people do, and get good results.
Formula Shell had a good UOA a while back, and so did GTX, both with quite high miles (like 8-10k IIRC)

 

[pbm]

I think your question is a very good one. My guess would be that the stability of a synthetic base oil enables it to go further before oxidation etc....start to degrade the oil.

 

[Mustang Man]

Well remember that (for example 5w30) if it is dino it is a 5w oil with VI improvers to make it 30 when hot whereas synthetic is 30 and is able to act like a 5w when cold due to the way it is made.

 

[Audi Junkie]

Originally Posted By: Mustang Man
Well remember that (for example 5w30) if it is dino it is a 5w oil with VI improvers to make it 30 when hot whereas synthetic is 30 and is able to act like a 5w when cold due to the way it is made.

 

[Gene K]

Originally Posted By: Mustang Man
Well remember that (for example 5w30) if it is dino it is a 5w oil with VI improvers to make it 30 when hot whereas synthetic is 30 and is able to act like a 5w when cold due to the way it is made.


Thats not exactly correct . Its actually a combination of base oils, flow improvers and VII's that meets the 60,000 cP @ -35C pumpabilty standard and still results in 9.3+ cSt @ 100C.

However you are correct in the basic idea that the Synthetics will have less (In some cases none) VII than a conventional and the viscosity (at 100C) of most of the base stock will be higher in the synthetic.

 

[Gene K]

Originally Posted By: rjacket
If add packs getting depleted are the reason to change oil, then, all things being equal, why wouldn't a conventional with the equivalent add pack to a synthetic, not go just as long?

Why can't you put a superior add pack (eg same as the one that goes into a synthetic) into a conventional and call it EP?


Basically you need additional additives to overcome the shortcoming of the base stock. The better base stocks today make this easier to accomplish. These oils already exist in the form of HDEO conventional. If you have a car that takes 10W-30 you could experiment with oils like Shell Rotella T 10W-30 for a long drain conventional. I used to run 9,000 mile drains on a mostly city driven 3800 Buick on the older CI-4 version of this oil.

 

[tig1]

There's more to oil than the add pack. Base oil makes up 80-85% of product. Synt. base allows for longer OCI.