what is progressive shifting

Wikipedia has a really good explanation/definition of this.

 

When the shift point (RPM) is different for each gear. It may only be 50 to 100 rpm per gear. I might not be 100% correct with this answer but this is how I understand it.

 

Progressive shifting is the art of shifting at the lowest rpms possible. Thus saving fuel and increasing your mpg

 

from wiki

"
Progressive shifting is a technique for changing gears commonly practiced by drivers of semi-trailer trucks. It is meant to reduce fuel consumption — something very important for drivers who travel several hundred miles each day.
Progressive shifting is accomplished by changing gears upward as early as possible when accelerating, while staying within the torque range. Each shift will go a little higher into the RPM, until the vehicle is in its top gear at cruising speed. After each shift is completed, the engine and transmission should be operating at or near the lowest rpm speeds recommended by the manufacturers of those parts.
As defined by KE =1/2 mv^2, acceleration is the process of gaining kinetic energy, so the greater the power delivered, the quicker it gains kinetic energy.
The best average acceleration in a truck with a Caterpillar C15 engine is achieved by going all the way up to 1950RPM, then shifting to a gear that will put the engine at 1500RPM, so that the truck is receiving as close as possible to maximum power throughout the entire time it is accelerating. This, however, is not progressive shifting, and has increased fuel consumption and wear on the motor.
Shifting at peak torque does not provide the maximum acceleration as even the engine maybe making the maximum torque, with each up shift, the mechanical advantage of the transmission is reduced."

i checked out there definition as it was mentioned in a previous post and i figured i would save myself the hassle and copy and paste because i couldn't have explained it much better myself.

 

In short, it's keeping engine RPM's very low as you're starting from a stop, and revving to slightly higher and higher RPMs at each gear, as you shift up

i.e. maybe rev to 800 going to 3rd, then 900, then 1000, then 1100, then, 1200, etc. It's an "old school technique", and many newer engines with manual transmissions will effectively "force" this type of progressive shifting operation on drivers via the engine software, if so programmed.

 

Going light on the throttle as you go through progressive shifting is part of the idea IMO. It isn't like you are romping on the throttle to hit that target shift rpm as quick as possible. Be patient with it. Progressive shifting is meant to save fuel and put less stress on the drive train.

 

A pain in the derrière if pulling 100,000 lbs on 8%grade and trying to get from low range to high range after stopping for flagman ... But hearing some guys revving it as high as it will go every shift I see why some company's use it

 

This technique is key for tank drivers who pull smooth bore with a product that likes to surge, only the progression is with every other gear. ie, shift at 1400 going into 4th, shift at 1250 into 4th over, then 1450 into 5th direct. Takes practice, but works great.