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I thought I would pose a question to the group regarding the Economy Mode on Allison Transmissions. A friend of mine always uses it and I never do. I asked him if he was able to tell factually that it was saving him fuel. He did not have any real proof but still “thinks” it’s better because of the lower shift point and less downshifting. To me these things lug the engine and increase stress on the engine and transmission. I am happy how my Coach performs in normal mode and like it to downshift when needed. I also manually select a gear that I want to hold instead of letting it up shift and downshift at certain speeds on hilly terrain.  I’m interested in what you guys do and why as a topic of discussion 

 

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I use the economy mode most all the time 

 

Especially in rolling hills.

Much less shifting , searching for the gear.

 

I certainly don't worry about milage 

As I am towing something??

Most time's 

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I have tried the Economy Mode a handful of times but only when the terrain is such that it would be useful like in Florida and other locations around the country. Most of the time I forget about it as the fuel savings is so insignificant that it doesn't make much difference whether I use it or not.

Any minuscule savings is usually chewed up while climbing the 6 mile Fancy Gap grade on I-77 going into Virginia. My pedal is to the floor the entire 6 mile climb just to keep the RPM's at 200 or slightly higher.

Edited by Dr4Film
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If you ever have a chance to attend a Allison seminar, they will change your mind on driving habits.  Did you know that Allison considers their transmission in a motor home as light duty use?  Chuck B

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Remember diesel engines work best when fed the right amount of fuel. Flooring the accelerator to climb a hill only wastes fuel. Manual downshifting keeps fuel/air mixture correct as long as you keep the rpms up. Basically the Economy mode is ONLY beneficial on rolling terrain. It reportedly eliminates 99% of downshifts from 6th to 5th according to Allison. In City driving your coach will downshift 200 rpm sooner and will waste fuel. I attended the Allison seminar at an FMCA rally and have not used the economy mode since. Just my experience....Dennis

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I’m still learning about driving our 2007 Monaco knight 330 Cummins/6speed Allison-my question is when cruising down the road at 65 mph the tach is showing about 1600 rpm.what is the optimal range to work in when manually shifting for grades or low speed situations and not lug the coach or over rev the engine? What is considered excessive rpm range?

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Can't say about the engines larger than mine, I have a Cummins ISC 350HP with a Banks Power Pack Kit, but for mine the optimum RPM's when climbing grades is around 2K. If the RPM's are about 1500 then I can feel the engine lugging. I will always manually shift the engine to keep the RPM's in the 2K range on any steep grades.

I would imagine that the ISB's are similar and most likely the ISL's. Not sure about the ISM & ISX engines or the DD's.

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2008 400hp, I've never used it, for the same reasons you gave.  I am  more concerned with the strain on the engine when lugging it, than saving pennies in fuel costs.  I haven't had the Cummins seminar, but I would enjoy attending someday.

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That is interesting about a chip for the ISM.   I have heard about the "Dirty fix".  I have the ISM also,    I attended several seminars at the Ramblin Pushers 419 with Allison and Cummins together.   The word was that the econo mode was for city driving.  They also said that it did not really do much one way or the other.

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I have the 500 hp ISM 11

I arrived home last evening from a 1,000

Mile trip

Saint Augustine area to Morrow county Ohio North of Columbus 30 miles.

I used the economy mode in rolling hills conditions,  always do. Much less shifting

If and when I remember to ??

I put it in econ. Mode in the morning and never release it..

I find , the way I am programmed. 

My sweet spot is 69 to 72 mph at 

16, 17 hundred rpm flat road cruising like Cincinnati North on I 71 to Cleveland or I 75 to Toledo 

 

Big, big hills I manualy shift and keep the rpms at 2,000 to 22 hundred?

How accurate is my tach ? Don't know.

Chipped ? Don't know 

the last two S.N. numbers on my engine indicate the engine was designated , manufactured for Fire trucks. 🔥

I have 125,000 plus  trouble free miles. 

Use very little oil.

No exhaust smoke.

I change all fuil filters every 3,000 miles.

engine oil, filter, coolant filter every  5,000 miles.

hydraulic fluid every 10,000 miles 

Like On Richard's run North of Charlotte, we chose 26 North to Ashville this week.and North of Chattanooga,  rt 111 to Sparta and Cookville. A heck of a pull up from the river.

 

 

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21 hours ago, pcpronze said:

That is interesting about a chip for the ISM.   I have heard about the "Dirty fix".  I have the ISM also,    I attended several seminars at the Ramblin Pushers 419 with Allison and Cummins together.   The word was that the econo mode was for city driving.  They also said that it did not really do much one way or the other.

I heard about the 'Ugly Fix', if that's what you're referring to.  I've heard about it with the DD60 and some with the ISX.  It is in the compoany's product list but I never before heard a motorhomer with it installed on the ISM.  I've looked on mine and cannot even locate the atmospheric sensor which it's supposed to replace.

On 4/8/2021 at 5:34 PM, Dennis H said:

Mine is a chipped ISM and my sweet spot is 1800....Dennis

 By 'chipped' do you mean the Ugly fix for the ISM or something else?

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When I bought it, it had been chipped to 525 HP. Didn't notice much difference except lesser fuel economy. I removed the chip and it's been great for over 100,000 miles....Dennis

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