Hello Everyone,

Can anyone recommend a 10w-30 oil for winter use on a 1985 300D Turbo? I have been using Shell Rotella 15w-40 year round but would like a thinner oil for better upper engine lubrication when cold. Temperatures can reach -10 F in this part of CT but usually hover in the teens for days. Mileage is 250,000 with little blow by. I am mainly asking this question because I can't seem to find a 10w-30 for diesels that is non synthetic. I don't mind paying for synthetic but I am hesitant because of possible leakage. Thanks!