Hello everybody. I recently changed my oil with a hengts filter, and valvoline dura blend oil (10w-40)... the upper part of the circle says API SERVICE SM, middle is SAE 10w-40, and the lower part is blank... I was just told to change that crap out because its not diesel rated... Help please? I've driven it a total of 100 miles with it in there, and theres nothing adverse going on... I also plan to drive <100 miles next week with my grandparents who are comming in from NV...

Should I change the oil to something else? If so, what would you reccemend (76 300d with the 617)... and can I leave that brand spanken new $8 filter in there?

Thanks alot, I REALLY appreciate it
~Nate