2017 GMC 6.0 Vortec - Manual Shifting?
I notice when I am towing my RV, my truck seems to try and down shift sometimes when climbing a hill before it should. Do any of you guys manually shift to get more power or save gas in these situalt...
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I don't know what truck you have, but my 2011 GMC Sierra 2500HD with 6 speed auto has the M position and +/- on the gear shift. My understanding and the way my truck works is that is the top gear the trans will use. For example if I am on the freeway and have some gentle hills and my transmission is shifting to 6th and then to 5th and then back to 6th, I can go to M mode and set it to 5 and it won't shift to 6th then. My manual states that it is not to used to "manual shift" transmission. It is nice to keep it from "hunting" and it helps keep the trans cooler since shifting up and down constantly generates lots of heat.
