I have been wasting fuel !

[oilburner]

I have always herd of people useing progresive shifting, but i always thought it was shifting at 1300RPM, utill i was reading a post on here about it. I have always shifted at close or about gov. speed of the engine, the frist truck i drove had a big cam cummins in it and to be honest that was the only way to get any thing out of it, it really had a sweet spot at 21 or 2200. I read about shifting at 1600 and 1700, so i thought the next time i haul i will try this with the ch. So i must say i would shift at 1600 in the low side when i frist tryed it i didn't think it was going to pull it out, because i am grossing around 92000, but it done it just fine, and the truck pulls harder this way i guess because you are keeping the engine in it's max touqe range. Now on the high side with the 13 speed maxitouqe trans i found shifting it at 1700 Rpm worked the best kept the smoke down, i have also found that out of 4 trips i can get almost another half a trip out of a tank of fuel, so all i have been doing is waisting fuel keeping the r's up around 2100 before i would make a shift. I have found pulling long grades like jellico mt on i 75, that if i down shift at 1500 that it will put it around 1800 when i get back in it, which it usally will pull back down to 17 or 1650 as long as i keep it above 7th direct, if i go below it wants to stay in the 1800 range, but you can back out of the pedal a little and it will still hold engine speed. This page has been very helpful and is full of information for not just mack owners but thoses that have brand x as you guys call them also, Thanks alot.

[Green Dash]

Congratulations on your epiphany!

You may be a late bloomer but you are still ahead of the many who don't understand or want to acknowledge that todays trucks perform better at lower rpms than in the past. Be sure to buy yourself something nice with all that extra cash that will be in your pocket instead of your tank.

[vision386]

Cost of fuel these days ANYTHING you can do to save money helps! personally,i drive smart,not as heavy on the throttle as i used to be LOL! only thing saving me is 90% of what i haul is under 20,000 Lbs......................................Mark

[rsb502]

Yeah I think everybody starts driving winding trucks out, but it just doesnt really help the truck or your wallet at all, I dont even look at a tach anymore I just give the truck about half throttle and when the torque drops off I shift it. I know they run a lot better at or aound peak torque than they will at max rpm for sure, I remember my old CH E7 400 would run up most hills at about 1550-1700 if I tried to run it harder it would pull back to 1600 so I just started driving it at about 68mph that made it abouyt 1550-1600rpm and it would do it up and down hill since it was already making the torque it needed to pull on out it never dropped off.

[bullhusk]

I have always herd of people useing progresive shifting, but i always thought it was shifting at 1300RPM, utill i was reading a post on here about it. I have always shifted at close or about gov. speed of the engine, the frist truck i drove had a big cam cummins in it and to be honest that was the only way to get any thing out of it, it really had a sweet spot at 21 or 2200. I read about shifting at 1600 and 1700, so i thought the next time i haul i will try this with the ch. So i must say i would shift at 1600 in the low side when i frist tryed it i didn't think it was going to pull it out, because i am grossing around 92000, but it done it just fine, and the truck pulls harder this way i guess because you are keeping the engine in it's max touqe range. Now on the high side with the 13 speed maxitouqe trans i found shifting it at 1700 Rpm worked the best kept the smoke down, i have also found that out of 4 trips i can get almost another half a trip out of a tank of fuel, so all i have been doing is waisting fuel keeping the r's up around 2100 before i would make a shift. I have found pulling long grades like jellico mt on i 75, that if i down shift at 1500 that it will put it around 1800 when i get back in it, which it usally will pull back down to 17 or 1650 as long as i keep it above 7th direct, if i go below it wants to stay in the 1800 range, but you can back out of the pedal a little and it will still hold engine speed. This page has been very helpful and is full of information for not just mack owners but thoses that have brand x as you guys call them also, Thanks alot.

Thats the way it used to be, peak torque between 18 & 2100 RPM'S............ And then came the constant horsepower Maxidyne 1200 to 2100 ! What a beautiful thing it was! Some of the new Detroit DD15's I have gives you peak torque off the clutch

BULLHUSK

[rsb502]

Hey oily, how's the mileage after driving that thing using the engine for a while instead of using your foot? Is it getting better, easier to do the longer you do it?