Pros and Cons of Synthetic Oil

[Marksman]

Some very informative reading.....

[sdowney717]

Truck diesels run AMSOIL synthetic and a submicron bypass filter and can get extremely long drain intervals. Around 500,000 miles on the same oil.

[sdowney717]

The Importance of Engine Oil Filters

On 2007 and later diesel engines, this is especially important because they are using the API CJ-4 standard oils. These CJ-4 oils, due to extremely tight restrictions in content to maximize the life of the new diesel particulate filters (DPF's), basically have additive packages of degraded performance. This means reduced anti-wear additives and low TBN's of only 8 to 9, rather than 10 to 14. At the same time, the EGR (exhaust gas recirculation) percentages have increased from 10-15% levels up to 25-35% levels, adding further load to the additive packages. However, a bypass filter will reduce the load on the additive packages, extending the life of the oil. In the case of Amsoil's CI-4 Plus diesel oils, a bypass filter will often extend oil life indefinitely - requiring only filter changes for 500,000 miles or more.

One advantage of a synthetic is if you can do extended drains.
The other is heat, heat on a synthetic, the oil breaks down less than crude oil.

[cburger]

Originally Posted by Marksman

Some very informative reading.....

Great attachment, very interesting read.

[Unicorn Dreams]

My Father was the 1st owner of UD which has a 4-108 in 1976 and put Amsoil in the engine until ho sold her in the 90's. Don't know what type of oil next owner used, but it wasn't synthetic.
When I bought her a couple of years ago I immediately switched back to Amsoil. Have used Amsoil in every engine I have ever owned, both used and new. The main thing to watch out for is that synthetic oil does NOT smoke like fossil oil so watch out for that.

[cburger]

Originally Posted by Unicorn Dreams

My Father was the 1st owner of UD which has a 4-108 in 1976 and put Amsoil in the engine until ho sold her in the 90's. Don't know what type of oil next owner used, but it wasn't synthetic.
When I bought her a couple of years ago I immediately switched back to Amsoil. Have used Amsoil in every engine I have ever owned, both used and new. The main thing to watch out for is that synthetic oil does NOT smoke like fossil oil so watch out for that.

Please explain why not smoking would be a problem?

[David M]

Oil has additives that get used up over time. This has nothing to do with how clean the oil is kept. An aftermarket filtration system obviously can not take care of this unless you can buy additives that you can add to the old oil. Can additives be purchased? If so, how you you ever know how much additive needs to be added other than by paying for an oil analysis?

How many oil changes would it take to break even on the cost of the aftermarket filtration system?

The pH of oil also changes which a filter cannot compensate for.