2007 R350 MPG inquiry
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Newbie
Joined: Apr 2003
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From: S.F. CA
2007 R350 MPG inquiry
Hello fellow enthusiasts,
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
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
Super Member
Joined: Nov 2017
Posts: 558
Likes: 114
From: San Francisco Bay Area
2006 R500
24 mpg is pretty darn good for a gas W251. 29 mpg is diesel territory. You were either driving slower than normal or had a significant amount of downhill from where you started. I get 19-21 MPG in the R500 on the highway but that's because I cruise at 75-80 mph.
1. Sport/comfort makes no difference in the top gear. Comfort mode starts in 2nd gear, shifts softer, and utilizes a 2nd gear reverse. Sport starts in first, shifts quicker, and uses 1st gear reverse.
2. RPM change between 6th and 7th at around 2000 RPM is about 200-300 RPM. I have 3.70 differential gears and cruise 75 at just under 2400 RPM (2000 RPM at 65). You would have 3.90 differential gears, which matches up with 2200 RPM at 65.
1. Sport/comfort makes no difference in the top gear. Comfort mode starts in 2nd gear, shifts softer, and utilizes a 2nd gear reverse. Sport starts in first, shifts quicker, and uses 1st gear reverse.
2. RPM change between 6th and 7th at around 2000 RPM is about 200-300 RPM. I have 3.70 differential gears and cruise 75 at just under 2400 RPM (2000 RPM at 65). You would have 3.90 differential gears, which matches up with 2200 RPM at 65.
Newbie
Joined: May 2022
Posts: 11
Likes: 2
From: Germany
Mercedes Benz R 320CDI 2006 Long version Luxury package
Hello fellow enthusiasts,
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
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
I know this is a very late reply, but I have just landed across. I will not step into technical details or numbers. I was in the same situation with my R320 CDI... Reset the transmission(turn the key to position 2, don't start the engine, fully press the gas pedal for at least 30 seconds, release the pedal, turn the key to position 0, don't opend the doors or use any other buttons or radio for at least 5 minutes then start the engine and drive, or there's another way model depending, key to position 2, fully press the gas pedal for 30 seconds, start the engine and drive) and you will see better transmission response at lower RPMs and slightly better MPG. And more life from your engine. More fun!
Newbie
Joined: May 2022
Posts: 11
Likes: 2
From: Germany
Mercedes Benz R 320CDI 2006 Long version Luxury package
Oh, that was something else, unfortunately. Well, the reset method is the cheapest, when no other faults are present. But, I found out that performing the reset helps a lot on long term use. The system learns the driver's style and at some point it needs a refresher.
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