manholt Report post Posted February 25, 2017 I have a Cummins, and know the shift points. My Lady friend has a Tiffin Phaeton, 2006, 40 foot, DP 350 Cat 2005. I have told her to downshift as needed for steep or long hill's . My question is, what are the approx., shift point's for up down, per rpm? For max torque? Carl Share this post Link to post Share on other sites
wolfe10 Report post Posted February 25, 2017 Carl, Peak torque is 860 lb-ft at 1,440RPM, so don't run below that with any significant load. Peak HP is 350 at 2,400 RPM which is also governed RPM. A good hill climbing speed for that engine is 2,000- 2,100 RPM. For those not familiar with mountain driving with a heavy vehicle, a good rule of thumb is to find a gear where you can maintain 2,000 RPM AND STILL HAVE A LITTLE THROTTLE LEFT (i.e. not at Wide Open Throttle). Share this post Link to post Share on other sites
manholt Report post Posted February 25, 2017 Thank you, I will pass that on to Linda, over breakfast ! Share this post Link to post Share on other sites
