At what RPM do you shift?

those rpms are too high unless you are trying to gain speed up a hill with a heavy load what you want to do is called progressive shifting starting off in your low range shift at about 1200 rpm and then when you get into high range shift at about 1100 and progressively get lower if conditions allow

 

if the lower range is what gets better mileage. why does my scangauge give me better mileage at the higher range.

if the lower range is what makes the truck move. how come my truck don't move till the higher range. cuz the powerband don't start till 1400.

the low range is torque, thei high range is power. better mileage, and lower egts.

i seen a farily new trans. get new input shaft bearings. cuz the driver drove in low range. was the mechanics response. don't remember the whole explanation as that was a few years back.

my scangauge showed better mileage at the higher rpm range. i used to drive around in 13th gear at 1400 rpms. now i drive around in 12th gear at 1575. 1800 rpm is the high range for cummins. according to cummins shop.

 

Your tranny and gears, load , grade ect,, have a lot to do with each truck , generally Down shift 1400 , upshift 1800. 18 speed . pretty much norm ,

 

Progressively higher RPMS when upshifting.. all downshifts are made at the same RPM, unless I'm "doubling down".. then its down idle.. raise the RPM's 600 and drop two gears..

 

Running cattle depends on the load I have on. When I'm really heavy I shift at 1400 and split the last gear in the basement and every gear on the high side. When I'm loaded heavy, I shift at 1500 and don't split anything, when I'm loaded with a normal load that would put me at normal gross I shift at 1400 with no splits. And when I'm light I shift at 1350 no splits. Empty hell I'm lucky to cross over 1250 I lug the hell out of that motor when I'm empty. Downshifts are at 1000 or so depending on load and road conditions. Normally it's 1000 in the city I keep the revs higher and the jake on. I've turned 2000 before after downshifting for more brake horsepower on my jake. Just depends on the situation and road conditions.

 

running in the lower rpms. torque range instead of power range. your actually making the motor work harder to maintain speed.

higher rpms. in the power range. the motor doesn't work as hard. therefore uses less fuel.

i didn't beleive it as first till i bought the scangauge tool. picked up .3 by dropping a gear and running in the higher range.

like 379. i'll run the lower range empty. but when loaded. higher range.

 

I've a 370 Cummins and a 10 speed. The book suggests downshifting at 1200 and upshifting at 1700. I normally run around 77,500 gross. In practice I find that downshifting around 1525 and upshifting around 1800 works best. It's probably not giving me the best fuel economy but my rig has a bad EGR valve and if I lug it too much then the #### thing just starts burping and farting. Truck is due to be traded by the end of the year so the shop doesn't want to spend the $800+ for an EGR valve repair.

 

I have too much drop off to run the higher range of my spectrum. After about 1500-1550 on upshifts I have to put my foot on the floor because of the power drop off which is why I use the ranges I do. I don't worry so much about fuel as I did before. Now with winter coming I'll be back to running the higher RPM ranges and getting deeper in the throttle. I broke loose a couple times last year due to my own stupidity using torque instead of HP. Ain't going to make the same mistake this year.