Ecodiesel Towing Report

[Dragonmaster13]

You need a slight downhill and back off the throttle and it will go into 8th and maintain it on the flats.

Interesting as Tow/haul is supposed to lock out 8th gear as it's too hard on the clutches in the second overdrive. I'll have to investigate further with mine as I've never seen 8th towing with an ED or a Hemi?

 

[silver billet]

I do like these reports. However, I don't think you're being fair to the Hemi.

I have a 3.21 hemi, towing more weight (5000) and a bigger front end because it's a travel trailer. And your truck sounds like it's exactly like my truck, just 1 gear further ahead (which is due to the fact that you're running 3.92 and I'm running a 3.21, so my 6 = your 7 etc).

My truck will enter 7th, but doesn't like it. It can run all day in 6th at 2200 rpms on flat roads. Downshifting to 5th or 4th very seldom (just like yours ocassionally hits 5th).

So other than a definite increase in MPG over the Hemi, I dunno, I think the Hemi is doing just fine.

 

[bill-e]

You need a slight downhill and back off the throttle and it will go into 8th and maintain it on the flats.

I've got 10k miles towing with the EcoD (3.55 and 3.92) and I know how to unload the engine to get it to upshift and I'm saying that both of my trucks in the tow-haul mode will not go into 8th no matter what I try. Like Kooch80 stated if I'm in normal mode in 8th sometimes it will stay in 8th for a bit when I flip the switch but mostly it immediately downshifts into 7th.

When I tow I put it into tow-haul and leave it there until I reach my destination. Maybe there is a difference in USA vs Ca software in this regard.

 

[bill-e]

Interesting as Tow/haul is supposed to lock out 8th gear as it's too hard on the clutches in the second overdrive. I'll have to investigate further with mine as I've never seen 8th towing with an ED or a Hemi?

That has been my understanding as well which is why I am surprised and intrigued by this discussion.

 

[tom318]

I towed a relatively light trailer (3000#) and it would sit in 7th for the longest time but would go into 8th in tow haul. Occasionally after a few minutes at a consistent speed (65-68) it would go into 8th. Then it would try to stay in it unless we really had a big hill. I wasn't a big fan so partially drove with tow/haul off and it would find 8th more often and more naturally in my opinion. When want 8th, I could only have 7th, when I wanted 7th, I could only have 8th or then 6th. I found myself thinking of this quote and cracking up from an old top gear episode "There is a place reserved in Hell for the man who put that gearbox in that car. And it's the ratios - it's a case of many are called, but few are chosen. And many who are first shall be fourth and many who are third will actually kick-down into second." James May.

 

[J-Cooz]

I've got 10k miles towing with the EcoD (3.55 and 3.92) and I know how to unload the engine to get it to upshift and I'm saying that both of my trucks in the tow-haul mode will not go into 8th no matter what I try. Like Kooch80 stated if I'm in normal mode in 8th sometimes it will stay in 8th for a bit when I flip the switch but mostly it immediately downshifts into 7th.

When I tow I put it into tow-haul and leave it there until I reach my destination. Maybe there is a difference in USA vs Ca software in this regard.

Weird. I snapped a photo today when I took the trailer back. It went into 8th multiple times.

 

[bill-e]

Weird. I snapped a photo today when I took the trailer back. It went into 8th multiple times.

That speed is right where I usually tow....maybe it is the load or those darn metric gears you have

 

[J-Cooz]

That speed is right where I usually tow....maybe it is the load or those darn metric gears you have

Haha. Metric everything except the MPG.

 

[gorilla57]

Mine shifts into 8th while in T/H mode. I was gonna lock out 8th because of the 2nd overdrive clutches, but the truck shifts into 8th and holds it fine. That is while it was towing a boat that weighs about 7000lb with trailer.

 

[Dragonmaster13]

Mine shifts into 8th while in T/H mode. I was gonna lock out 8th because of the 2nd overdrive clutches, but the truck shifts into 8th and holds it fine. That is while it was towing a boat that weighs about 7000lb with trailer.

Might be my 7600lb kite that I tow. It likes 6th and 7th on low grade down hills only. Never seen 8th.


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[WXman]

My experience was the same with my 7x14 enclosed trailer. I'd see 14 MPG hand calculated almost every time I pulled it. Truck would use 8th gear, even with TH mode on. I was very happy with that.

Now, with the 8.5x24 it's a different ballgame. I have to lock out 8th and force the truck to stay in 7th so that it doesn't loose too much momentum climbing hills with cruise control on. It'll try to hold 8th as long as possible and will lose up to 10 MPH. Then, by the time it finally downshifts it goes all the way down to 5th to catch up. So by forcing it to stay in 7th it keeps momentum better.

 

[J-Cooz]

My experience was the same with my 7x14 enclosed trailer. I'd see 14 MPG hand calculated almost every time I pulled it. Truck would use 8th gear, even with TH mode on. I was very happy with that.

Now, with the 8.5x24 it's a different ballgame. I have to lock out 8th and force the truck to stay in 7th so that it doesn't loose too much momentum climbing hills with cruise control on. It'll try to hold 8th as long as possible and will lose up to 10 MPH. Then, by the time it finally downshifts it goes all the way down to 5th to catch up. So by forcing it to stay in 7th it keeps momentum better

That 8.5 x24 is a big girl. That's a massive amount or wind resistance. The 7x16 towed nice and I was happy with the Ecodiesel performance. I think an 8.5 x 24 is pushing it for a half ton even if the numbers work.

 

[bill-e]

I wonder if there is a tranny TSB for this, it really shouldn't be going into 8th. I didn't by my 1/2020 built truck until 8/20 so who knows what flashes were applied.

 

[WXman]

So yesterday I put my tractor in my 24' enclosed trailer and hit the highway. Roughly 7,700 lbs. total weight.

First of all, the Timbren SES is amazing. No excessive squat at all and truck rode very nice.

Secondly the EcoDiesel surprised me by continuing to use 8th gear when it could on the interstate. I locked 8th out though, as I usually do, to prevent loss of momentum on the really steep hills. Tow/Haul mode was on. Truck would just cruise right along in 7th gear and did an amazing job. It honestly performed better with that load than I expected.

I will still go Ram 3500 next time around, but this trip down the road made me realize I don't have to trade trucks right now. I can live with this until I get closer to end of lease.

 

[Rossum]

I have to lock out 8th and force the truck to stay in 7th so that it doesn't loose too much momentum climbing hills with cruise control on.

That's quite surprising to me. Mine (a 3.21) will downshift out of 8th before losing any noticeable speed at all on hills with the cruise on, and that's w/o a trailer! I wonder if there's some difference in the programming between 2020 and 2021, or between the 3.92 and the 3.21, or if it behaves differently when you've got a trailer plugged in.