What RPMs should I be upshifting/downshifting at?

Depends. Some engines like more rpm's, some like less. After awhile you will be able to shift by ear and feel. Good Luck

 

Newer trucks usually prefer lower rpm's. My Cascadia usually likes a shift to start around 1000-1200 rpm. But in driving school we used antiques that were made before anyone knew what a mpg is.

 

Tell that to my 2017 579, she grumbles when you shift under 1500-1600

 

Yikes, what engine/tranny you got?

 

MX13 with an eaton 13, It seems to like shifting right around 1550 or so at 80k. Much over and it lurches a bit and much under it lugs after the shift.

 

Wow what sort of mpgs you get?

 

Around 5.8 loaded so far. Was getting 9.1 empty. But i also run an end dump not a road truck so we tend to burn more fuel and always run 80k (totally only 80k never more....../s). I know when i drove as a company driver for the place im leased, his 389s were getting 3.5 to 4.5 average. But those are also 550 cats with 18s and cruise at 1700-1750

 

Nowadays companies are all in love with the idea of progressive shifting, and in modern trucks that are designed for lower RPMs that's fine. But when you are heavy you should make sure that you shift at a point where the engine will still be just above peak torque when you start into your new gear.


For ordinary upshifting, a co-worker who was a trainer for many years said that he used to teach his students "the rule of fives." I had never heard of this so I asked him to explain it to me, and he explained it like this:

When you are accelerating and your speedometer reaches a speed that ends in 5, you should upshift into the gear that is the sum of the numbers the speedometer needle is pointing to. For example, when the speedometer needle points to 25, you should be shifting into 7th gear because 2+5=7. Similarly, when the speedometer reaches 35 you should be shifting into 8th because 3+5=8.

I have found that when running heavy, it is sometimes necessary to use a few more RPMs, and therefore to go a little faster, in each gear before you shift that way you don't lug the engine when you shift into top gear and the torque drops.

Eventually you will learn to shift by the sound and the feel of things, but while you're still learning it's good to pay closer attention to your instruments.

 

When it starts getting too loud shake the stick. Unless you want to go down a hill really fast...really really fast.