At what RPM do you shift?

I guess I got a question for 379 in refrence to you hauling cattle I noticed here in minnesota a lot of cattle haulers tend to drive on the fast side and a little crazy espically when empty is it that high pressure I assume you get paid by the weight or head count?? I dont know but just so I understand why some guys drive so fast is there something I am missing that is the reason for this I assume it is a pain in the ### to get cows to coperate sometimes which makes things that more hard pressed??

 

what rpm you shift at will depend on engine trans combo as well as weight and grade. took me a while to get used to driving my 60s detroit because i had always been in cats and cummins you were up shifting at 14-1600 down at 12-13. i run this 60 series out to about 18 before up shifting and down at 13-14. 13 speed and 18's you can shift sooner than a 9-10 speed because you have less rpms between your gears when you split.

loaded light or empty i shift lower rpm than heavy
shift your low side lower than your top side. your first few gears on your low side you bearly need any rpm to shift them 11-12 as you get closer to the top side start taking it out a little further. by the time your hitting your top 2 gears in the high side you should be taking it up high enough that when you hit your next gear your are in the power band.

also most engins should not be pulled hard on below peek tq, if a motor has a peek tq at 1200 you should never be full throttle below 1200 this can cause engine damage

 

It really depends on the motor and the trans.

A 13 speed normally has around 200 rpm in between shift on the high side. A 10 speed has more. A cat likes to be 200 rpm less then a detroit. In any case, 1700-1850 is a bit high. I have a Detroit and go in at 1200 and out at 1600.

 

Lots of opinions on what RPM to shift at and nobody has a clue what engine, transmission, rear end it is we are talking about.

 

Im currently driving a 2014 Peterbilt 389 with a 500 hp Paccar motor and an 18 speed transmission. I haul a scrap trailer and loaded I usually weigh in at 115,000 -140,000 lbs. I've been up shifting at between 1600-1900 RPM's. I'm being told that I should be up shifting between 1200-1500 RPM's but for the weight I'm pulling it seems kinda low. Any help would be appreciated.

 

Considering that we are in a tanker forum, my answer is: shift at whatever combination of RPM and road speed will allow you to smoothly gain/reduce momentum and minimize load surge.

It's going to vary with equipment specs, load density, percent innage, grade, and traction.