Best oil for 500SEL

[Brasilia Driver]

OK. . . I've done a search and haven't found anything revelant to my specific question.

I have a 1984 500SEL with ~250k on it. About 3,000 miles ago, I switched to Shell Rotella T 5W-40 Synthetic. Live in the mountains and wanted a good multi-season oil.

Shortly after I noticed some oil new oil drips, but this is to be expected with synthetic oil.

Recently, I was reading the lable on the Rotella, and found it was geared towards diesel engines.

My 500SEL is beautiful, and I view good oil as being cheaper than an engine rebuild.

My question is if the Rotella is a bad oil for my car, and if so, what oil should I switch to? Are there any synthetic oils that might slow the leaks (the car didn't leak prior to the synthetic). If the Rotella isn't a bad oil, are there any oils out there that might be better, or worth the extra couple of dollars a quart?

Thanks!

I didn't know or think that Rotella was a synthetic. I know it has special additives to handle soot/particulates because it's generally recommended for diesel engines.

You might consider an oil that's heavier than 5 weight. I've used 15W-50 Mobil 1 for years both in Minnesota and in Arizona.