I recently changed oil using Delo 400 15W 40. I read several posts about synthetic oils, and other brands of non synthetic. Would like to get opinions on both. Also, if I decide to switch to synthetics, is there anything special I have to do, like flush, etc.?

Driving conditions
Stop and go, plus freeway travel. Ambient temperatures range from 116 in the summer to about 40 degrees in the winter.

There is more than enough discussion on oil in the forum archives to allow you to read for weeks.

Every single possible opinion has already been rendered and there is no need to do it again.

Just search "oil" and be prepared to read for awhile.

Additionally, opinions on oil are rarely based upon any solid evidence of performance. Nobody can ever tell you that one oil performs better than another oil............the engine doesn't care unless you observe it for 100K miles or more.

If you use a diesel rated oil (the best ratings are CH and CI), and change it on a "regular" basis, you don't need any more information.

Should have searched the forum.

The last box of Delo I got at Costco is rated CJ. Has that been determined to be inferior to CH and CI?

Sixto
87 300D

CJ is the new standard required for the 2007+ diesels.

Well............I clearly don't keep up with the times............

That being said, he's probably OK with CH or CI.