So I now have this beautiful 6.7L with a 6 speed auto. It performs great when I haul heavy, but I'm a bit confused when driving around town with little or no load. If I just leave it alone, the tranny will upshift by itself all the way to 6th gear even if I'm doing the city speed limit. I don't know if driving around at 900 rpm is very good for the motor. Should I be using the button shift to lock out 5th and 6th for around town? That leaves me in 4th running around 1200-1500 rpm. Which is better?

 

this is just me but id prefer to keep my rpms around the 1200-1500. i dont like any little bit of load on my engine at lower rpms

 

Im no expert by far but on my 03 which i purchased recently I have been turning off the OD in city traffic to let the engine run about 1600 to 2000. I also dont like it loping around in OD or shifting up and down alot. I was also wondering if this is a good idea?? I dont mind burning a little extra fuel if it is better for engine in the long run, I actually wonder if it might be better on fuel?

 

Hi,
I have been using the toggle switch on the gear selector to toggle out 5 and 6th gear in the city. I tend to watch my RPM's and EGT's and I have found out that 4th gear in the city is best gear to be in. My RPM's tend to be around 1850 to 1900 RPM'S at 45 MPH and at 30 MPH they are closer to 1500 RPM'S.
Jim

 

I just drive mine and have 110k. The only thing I do is turn the Ebrake on to help keep the turbo from sooting up

 

Drive it like ya stole it.

 

I use the toggle and run in 4th everywhere in the city unless I get on the Ring Road in Hooterville, I mean Regina.
I use tow haul and the brake all the time.
My sig tells you how many miles I have on this truck.

 

sweet! like that sig. thats the only way......

 

I lock out 5th and 6th as well in town, I hate when it shifts into 6th at 40 mph. No problems so far.