Hello All,
After my third week of owning an 85 300SD, 225k miles, and reading this forum I have an OIL question. Please bear with me guys!
The previous owner of this car has used Valvoline 20w50 for the last 95k miles. After reading the forum daily, I'd like to switch to 15w40 Delvac, or Delo or Rotella...a DIESEL oil so to speak.
My question is, in view of the fact that this engine runs great, will there be benefits to switching to the Delvac, or should I stay with the stuff it's been getting every 3000 miles for several years. There are no oil leaks, little blow-by, and I don't want to take chances...but if the car would benefit, I will do it.

Thanks Everyone!