2007 R350 MPG inquiry
My wife drives a 2007 R350 with 90K. I recently drove it after not having driven it for at least a year and suspected the RPM of the engine to be higher than I remembered from the last time I drove it. While cruise control set at 65 MPH the readings that I observed is a little over 2100 RPM, and at 70 mph a little over 2200 RPM.
It’s possible that it’s normal and I just don’t remember it correctly but it still feels like it’s too high. When I shifted from seventh down to six the rpm only went up 200 RPM. When I shifted back up to seventh again it only dropped 200 RPM. All of the other gears had a 500 to 600 RPM change when switching.
The fuel mileage at 65 mph in comfort mode with cruise control on was observed to be 24 mpg after 10 minutes of driving. I remember getting 29 MPG in the past.
I have 3 questions for the group.
1. What should the RPM be in comfort mode at both at 70 MPH and 65 MPH?
2. What is the RPM drop ( or increase) at those speeds when shifting between 6th and 7th gears?
3. After resetting the “after-start” trip computer while cruise control is set to 65 MPH, what is your MPG reading say after 10 minutes of uninterrupted driving?
If you have an older R class and can report back your findings I would greatly appreciate it.
happy new year to all!
BSB



