so you can have instant on demand torque?
GL320 Speed vs RPM
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From: Terrell, Texas
2008 GL320CDI, C6 Corvette, 1969 Corvair Convertible
GL320 Speed vs RPM
A new GL320CDI owner here with a question. Just got my GL320 after years of Ford Powerstroke diesels. My Powerstrokes would loaf along at about 1750 rpm at 70 mph with 3.73 gears. With a seven speed auto, two overdrives and 3.45 gears, I was suprised to find my MB running at 2000 rpm at 65 mph. I can't seem to find the ratios for the overdrives, but it seems like this is a little high. Is this the normal rpm range? An online review by Edmunds, I think, said they were hitting 2000 rpm at 65 in 6th gear, and it dropped even lower in 7th. Only 325 miles so far, but am I not getting into 7th? Other than that, love the vehicle. Thanks for the help.
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From: Spicewood, TX
2008 GL 320, 2007 Silverado LTZ C3500 Duramax Turbo Diesel
A new GL320CDI owner here with a question. Just got my GL320 after years of Ford Powerstroke diesels. My Powerstrokes would loaf along at about 1750 rpm at 70 mph with 3.73 gears. With a seven speed auto, two overdrives and 3.45 gears, I was suprised to find my MB running at 2000 rpm at 65 mph. I can't seem to find the ratios for the overdrives, but it seems like this is a little high. Is this the normal rpm range? An online review by Edmunds, I think, said they were hitting 2000 rpm at 65 in 6th gear, and it dropped even lower in 7th. Only 325 miles so far, but am I not getting into 7th? Other than that, love the vehicle. Thanks for the help.
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From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
That said, at 65 I'm usually out of gears (it's already in 7th). I think maybe it really is just that the engine has to work a little harder to produce that much power from so small a powerplant.
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From: N. Illinois, USA
2021 GLS450, 2015 E250BT 4Matic, 2007 GL320CDI, 2005 SLK350, 2001 SLK320
2000 rpm at 65 mph
My GL320 also runs 2000 rpm at 65 mph.
For comparison, my 3.5L V6 gas-powered SLK350 with the 7-speed tranny runs 2200 rpm at 65 mph.
And my 3.2L V6 gas-powered SLK320 with the 5-speed tranny runs about 2500 rpm at 65 mph.
So the diesel engine revs the lowest of the three. But, like you, I was expecting even lower revs from a diesel engine mated to a 7-speed tranny.
For comparison, my 3.5L V6 gas-powered SLK350 with the 7-speed tranny runs 2200 rpm at 65 mph.
And my 3.2L V6 gas-powered SLK320 with the 5-speed tranny runs about 2500 rpm at 65 mph.
So the diesel engine revs the lowest of the three. But, like you, I was expecting even lower revs from a diesel engine mated to a 7-speed tranny.
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From: Terrell, Texas
2008 GL320CDI, C6 Corvette, 1969 Corvair Convertible
Thanks for all the information, I guess my vehicle is on par with everyone elses then. I was just concerned as I am usually in the 80 mph range when I travel, although I haven't hit that speed yet due to so few miles on the vehicle, but was just concerned that it might be running 3000 rpm or more at that range, and for 1000 mile trips, it just seemed like alot. I will try using the manual shifters next time I'm on the highway.
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Joined: Apr 2008
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From: Central Arizona
Dodge 3500 diesel, Jeep Commander
The rpm seems about right for the size of the engine.
My Cummins turns 2250 at 75mph, but its much larger and heavier.
Turbo speed only affected by the exhaust volume/speed, not the engine rpm.
It all seems right to me.
May you have many enjoyable miles.
My Cummins turns 2250 at 75mph, but its much larger and heavier.
Turbo speed only affected by the exhaust volume/speed, not the engine rpm.
It all seems right to me.
May you have many enjoyable miles.
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From: Scottsdale, AZ
2007 GL320 CDI, 2001 TJ Rockcrawler, 2005 Scoobie STI
According to the specifications for the motor, the 3.0 CDI in the GL puts out 398 lb-ft @ 1,600 - 2,800 rpm, so at 2000 RPM that puts it right in the middle of the fat torque curve, which is really the most efficient spot in the engine's operating range, so it makes sense.
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From: Scottsdale, AZ
2004 RX330, 2008 Scion xB, 2001 Honda Insight Hybrid, 2010 Toyot Prius v ATP
According to the specifications for the motor, the 3.0 CDI in the GL puts out 398 lb-ft @ 1,600 - 2,800 rpm, so at 2000 RPM that puts it right in the middle of the fat torque curve, which is really the most efficient spot in the engine's operating range, so it makes sense.
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From: South of the Mason Dixon, North of the Gulf
2007 GL 320 CDI, 2008 M5
According to the specifications for the motor, the 3.0 CDI in the GL puts out 398 lb-ft @ 1,600 - 2,800 rpm, so at 2000 RPM that puts it right in the middle of the fat torque curve, which is really the most efficient spot in the engine's operating range, so it makes sense.
But you've got to love the instantly available torque for passing and towing at highway speeds.
