Allison Transmission Mode Button

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stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Allison Transmission Mode Button

Post by stuplich@ymail.com »

Save fuel and help your motorhome operate at peak performance by learning how to manipulate the transmission’s shifting schedule.
https://familyrvingmag.com/2012/03/01/a ... CQogH-GZAw
(By Brett Wolfe, March 2012)

Thanks Brett
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
sweetbeet
Posts: 11
Joined: Tue Aug 25, 2020 8:59 pm

Re: Allison Transmission Mode Button

Post by sweetbeet »

Wow I drove my rig 12 k miles and never saw the use for this I will see if it helps the economy! I average 6.5 mpg now, but I am pulling a toad and have a heavy foot! Got A long way to go and a short time to get there!
Ruth Irons and (Mom) Doris Wagner
Argyle, Tx
2007 Safari Simba 38STS FRED Toyhauler (for electric wheelchair access)
Toad: Dodge Caravan converted for wheelchair access.
Mom is 88 years old, an amputee in wheelchair, she still ministers all over USA.
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: Allison Transmission Mode Button

Post by wolfe10 »

sweetbeet,

What are you driving? What engine? What speed?
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
astrnmrtom
Posts: 167
Joined: Thu Oct 31, 2019 8:49 pm

Re: Allison Transmission Mode Button

Post by astrnmrtom »

I am trying to get into the habit of using this feature. I'll be curious how much it improves my mileage. Even a fraction of a MPG would help.
Tom and Pris Masterson, w/ Buddy the 18 year old Siamese cat.
1998 Serengeti 3706
300hp Cat 3126, Allison 3060
900 Watts of Solar
17cf, Fisher & Paykel residential Refrigerator
Dragging four telescopes around the US seeking dark skies.
wolfe10
Posts: 222
Joined: Sun Oct 27, 2019 4:12 pm

Re: Allison Transmission Mode Button

Post by wolfe10 »

astrnmrtom wrote: Sun Sep 06, 2020 3:00 pm I am trying to get into the habit of using this feature. I'll be curious how much it improves my mileage. Even a fraction of a MPG would help.
The answer is "IT DEPENDS".

On I 10 across Louisiana (i.e. dead flat except 2 bridges) it would make zero difference-- you would be in 6th gear in either mode.

Continue west on I 10 to the Texas hill country. Lots of short, somewhat steep grades. In economy mode you will stay in 6th gear a lot more of the time-- therefore lower RPM, therefore less diesel injected. In power mode/regular mode, you will be downshifting on most grades-- using more fuel.

And worse: hit that hill country stretch with the exhaust brake on! Huge hit on MPG-- instead of building a little momentum on the down grades, you would be braking, then pretty quickly to wide open throttle to climb the next grade. With the speed limit out there of 70 or higher, and most of us driving 60-65, the smart move is to build a little speed on those downgrades (again, they are not long enough to require care in descent).
Brett and Dianne Wolfe
Ex: 2003 Alpine 38'. Ex 1997 Safari Sahara. Ex 1993 Foretravel U240
Moderator, FMCA Forums 2009-2020
Chairman, FMCA Technical Advisory Committee 2011- 2020
Moderator, http://www.dieselrvclub.org/ (FMCA chapter) 2002-
sweetbeet
Posts: 11
Joined: Tue Aug 25, 2020 8:59 pm

Re: Allison Transmission Mode Button

Post by sweetbeet »

wolfe10 wrote: Fri Sep 04, 2020 9:21 pm sweetbeet,

What are you driving? What engine? What speed?
So lets start by saying (justification for my action) My 88 year old Mother ministers all over USA teaching, kicking the devil out. So there are times that we have a long way to go and a few days to get there. I have been known to do 600 plus miles in a day. I think my record was 700 plus. But I try at all cost to quit before it gets dark if I can. I HATE driving at night so the rig needs to be moving in the morning when it is light enough to see. With a handicapped mother needing to take potty breaks and fuel breaks and feeding her and dressing her makes for a long day, driving and caring for her and the rig. So when I go, I am forced to push it! One day maybe I can find a man that wants to join me in this adventure, but for now it is Mom and me. The good news is I was a farmer, welder, auto mechanic and EMT, when I was a younger gal, so I can fix it or doctor it or glue it back together when it breaks. I do also have a class A CDL. Three of my basement boxes have only tools in them. I must admit I have fixed most things on the road and did not need to ask for tools or duct tape or bailing wire because I carry it all!

So our rig is a 2007 Simba Toyhauler 38TST, FRED 5.9 Cummins. Toad: Dodge Caravan Handicap converted, Fully loaded always, You have no idea what you have to haul with a handicapped person, I have a hospital bed in garage area for her, next to it tied down to the floor is a commode, I have a custom made box for her Cpap and all her night meds and supplies, a Craftsman rolling tool box that is all her stuff and Doctoring goods, the back side of the box is where her computer sits, with a pull down table, I even have a spare backup small electric wheelchair we haul because if she breaks down we are fried! I carry folding ramps and use them at churches to get her on the platform, I carry full water and propane, We stay only in truck stops until we get to where we are going for her next meetings, so I need all the tanks both full and empty when we hit the road! I go the posted speed limit when I have the long days (over 400 miles in a day) , and Yes, if the posted speed limit is 80 we will do 80 but that is where I draw the line. haha This rig runs so nice, but for all you that are worried I am pushing it too hard, I do watch the EGT's and if it goes above 1300, I will slow it down and keep it happy. If I have under 300 miles I need to go for the day, I keep it at 67 MPH ( even if the speed limit is higher) and enjoy the ride. This rig has a HappiJac Queen sized drop down front bed where I sleep so it is nice we both have our space. We get 6.5 miles to the gal, day in day out. 7 mpg is a good tank but even when I try and drive mid 60's it still never sees above 7 mpg.https://library.rvusa.com/brochure/2007_SimbaFD.pdf I do hope the mode in economy will help a little, but with my heavy foot I doubt it!
Ruth Irons and (Mom) Doris Wagner
Argyle, Tx
2007 Safari Simba 38STS FRED Toyhauler (for electric wheelchair access)
Toad: Dodge Caravan converted for wheelchair access.
Mom is 88 years old, an amputee in wheelchair, she still ministers all over USA.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Allison Transmission Mode Button

Post by TDJohn »

Ruth,

Cummins engines don't like high EGTs, I would suggest not to exceed 1200 degrees, unless they are really really short spurts.
BTW, the lower the EGTs while you are going down the road, the better MPGs you will get, so you can use the EGTs to find the sweet spot where you will likely get better fuel mileage.

Kudos to both, you and your mother, for all you work and persistence!!! Much respect to both of you!
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
sweetbeet
Posts: 11
Joined: Tue Aug 25, 2020 8:59 pm

Re: Allison Transmission Mode Button

Post by sweetbeet »

https://shopspeedhouse.com/blog/egts-ex ... s-too-hot/
How Hot Is Too Hot for EGT's?
Based on our own experience in the sled pulling and drag racing world, we can definitely say that any engine running at 1,800 to 2,000 degrees EGT for more than a second or two should be rebuilt every season and may incur turbocharger, cylinder head, or piston damage during the season. It is just too much to ask a diesel to run at those types of temperatures and expect it to live a long life. For towing, we'd say a sustained 1,200 to 1,300 degrees is a safe number, with occasional spikes of up to 1,500 degrees when climbing grades being an acceptable risk. The concept of EGT is analogous to putting something in the oven. You can put your hand in a hot oven for a second or two, and nothing will happen. Leave it in there, and you'll get burned. The same thing happens in a diesel engine. The longer the engine spends at a high EGT, the more likely it is to become damaged.

I am going to be going to injection to lower the EGT AND RAISE HP!
https://www.snowperformance.net/diesel- ... no-500.asp

Snow Performance has combined performance, quality, and ease of installation in this new water-methanol injection kit designed for all Dodge 5.9L Cummins owners who demand colder EGTs while towing heavy loads. The Diesel Stage 3 Boost Cooler utilizes a 2D mapped controller that commands injection based on boost pressure and EGTs (exhaust gas temperatures) to maintain extremely cold air inlet temperatures, 100-300 EGT decreases, decreased emissions, cleaner engine components, and increased fuel economy all while giving 65+ HP to help pull large hills with easy effort while towing. A must have for the diesel enthusiast that is concerned about the longevity of his truck that sees heavy towing. Non-invasive, the Diesel Stage 3 Boost Cooler controller is designed to mount on the steering column or the dash so no drilling/marring of the interior needs to take place or additional gauge pods need to be purchased. Functions as a boost gauge, water-meth controller and EGT monitor all in one! 7 Gal Tank included for trip ready installation. Recommended for all daily driven Dodge 5.9L Cummins that see heavy towing where EGTs become dangerously high. Need a CARB E.O. # for your state? No problem! See part# SNO-50100 for 50-State legal system.
Ruth Irons and (Mom) Doris Wagner
Argyle, Tx
2007 Safari Simba 38STS FRED Toyhauler (for electric wheelchair access)
Toad: Dodge Caravan converted for wheelchair access.
Mom is 88 years old, an amputee in wheelchair, she still ministers all over USA.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Allison Transmission Mode Button

Post by TDJohn »

Keep in mind that sled pulling and drag racing people/companies usually have very large budgets, so they are able to take a bit more risk and they also run for very short duration. Pulling a quarter mile in 11 seconds is very different than climbing a long mountain grade, or heading into a head wind at 70 or 80 mph for hours at a time. All I can tell you is those 5.9L cummins engines (and the 8.3L also) are very tough durable engine that were originally designed for agricultural use, but...their one big weak point is that they don't like high EGTs. It is your rig, and you do as you please, but if you want long engine life on your coach, you should avoid sustained EGTs above 1200, preferably below that threshold. You also might consider going to a larger diameter more free flowing exhaust, this will help lower EGTs considerably.

Have you ever considered propane injection?

Just food for thought... ;)
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
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