Today im driving the truck in traffic, i had my hand kind of resting on the shift lever and i guess i bumped the manual shift button down twice.....mind you im in "D" Not "M" the transmission display on the dash showed 1-4 the tranny acted like a 4 speed shifted down to 1st and up to 4 and stopped there......it would not shift to 5th or 6th....i thumbed the switch up one 5th light up on the dash and it acted like a 5 speed............maybe this is a good option to keep from lugging pulling or in traffic to help keep higher RPM's for cooling and AC????? dont know but its pretty cool!!!!!

 

Chevmn56 - yup.. it does that. It allows you to let the truck shift like an auto, but force it to stay outta higher gears. Handy if you're running thru hills, and it keeps shifting into 6 just in time to hit the next incline. Lock out 6th, and 5th if need be to keep it from constantly shifting.

 

I use this pretty often

 

Yep. I've found that if I'm towing at 60mph I get better fuel economy and performance if I lock out 6th. The thing wants to get to 6th gear really badly and it's annoying most of the time.