I'm on a road trip in Oregon and Washington. Today I was driving 80 MPH at 3800 RPM. The RPM seems high for that speed. Can anyone with a similar car let me know what their car does?

It would be nice to know the RPMs at 60, 70, and 80 mph for these 300SDs.

Thanks!

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1st MBz: 1982 300SD
2nd MBz: 1987 300SDL
3rd MBz: 1995 S420
4th MBz: 1987 190DT
5th MBz: 1984 300SD w/1983 300DT engine
6th MBz: 1999 C230k I'm 3rd owner, got it w/57,235 miles.
and manages Mom's 2007 R320 CDI