Newbie- oil brand/grade question

[AlexCole]

I have seen many discussions on brands/grades of oil to use, which have only led to further confusion on my part. This is my first Mercedes and also my first diesel. I have replaced the brake master cylinder and a rear caliper, so not completely mechanically challenged. The owner's manual recommends 10w40 and 10w-50 for year round usage. NW Ohio is very cold in the winter (sometimes in the teens or below), but relatively warm (80's-90's) in the summer, so I am looking for some recommendations on oil for summer and then later on for winter driving. Thanks, Alex.

Any 15W40 non-synthetic or 5W-40 synthetic is fine for year-round use.

[Jeremy5848]

Depending on miles driven during the year, personal preference, etc., you might consider a non-synthetic during the summer (less expensive) and a synthetic during the winter (better cold flow characteristics, easier starting). Fewer miles driven, consider a synthetic and change it once a year.