I have a beef with the notion Eric extended on drain intervals for synthetics in diesels. There are a lot of trucking companies out there running 40-50 thousand miles between oil changes on heavy trucks with synthetics. Chevrolet sets the drain interval on my diesel pick-up at 10k miles, I have two Dodge diesels that reccomend 7500mile intervals. The last two use dino oil. I have done oil sampling on these trucks and the oil is still servicable at 10k miles, that includes soot and corrosives content. The bottom line, without trying to start another endless oil discussion, is that oil lasts a LOT longer than most people think, certainly longer than Jiffy Lube wants you to believe.
Back on the topic, unless you were driving a bunch more miles per year, stay with your"known quantity" 380SE. I find it doesn't really pay until you start racking up 50,000+ miles per year. I have also found that while a diesel may seem to require more attention, they really don't, it is just a different set of needs. Overall costs are very similar, fuel consumption is the major factor, and with domestic diesel trucks engine longevity is MUCH better on most diesels. As you already know,an MB gasser lasts an awefully long time
