manipulating shift points/ lowering rpm's

[silverado4991]

Hey all, I have a question concerning my 2012 25hd silverado's 6l90 trans. When driving in normal freeway traffic not pulling, I have noticed that while running 70 mph, I am taching right around 2000 rpm's,which seems to me a little high. Is it possible to use a transmission tuner/engine tuner to try and get the engine not to run so high? I have towed in tow mode,and noticed significant points to when the transmission shifts, just wondering if it can be maniplated in the higher gears. 

Thanks, and don't beat me up too much(lol), I am not versed well with the newer stuff.

Robert

[Formulabruce]

 That trans has a .67 OD (final) , tied with the TH2004R for highest gear ratio in a RWD vehicle. My friends 2012 goes the same. That is just slightly above the begining of the torque band ( where some decent horsepower exists) IF you can keep that tach at or below 2K you Will save fuel... You could also jump up a tire size and keep the width, and gain a couple MPG with some Road tires ( No huge sipes) 

[dewfpo]

2000 rpm is not high for an HD at 70 mph.

 

DEWFPO

[GP9]

Mine is also a 2012 6L, 3:83. It seems to go at about 1800-1900 rpm @ 70mph. I had the old 4L80 in my last truck with 4:10, and it did 2500 rpm @ 70 mph. I think you’re in the right ball park for how it’s supposed to run.

[bgbdwlf2500]

you cant do anything through the engine or transmission as it is using the top gear. you could change the rear end gearing however and do what you want. would have to do front and rear if its a 4x4

[Brendan Corr]

you're fine, my 2002 6.0 runs about 2600 at 70, and almost 3000 at 80, but then again, it has the 4l80