What do you consider lugging a ho 6 speed ?

[Turbo Terry]

On old 99 5.9 I thought 1500 rpm or below. But that was a four speed auto. This 6 speed is always trying to be in 6 gear and the rpms are way low. Less noise better fuel economy I suppose. But I think 1800 rpm is about the best. Or not to worry The truck has a lot of torque and the computer will take care of it ?? Your thoughts

 

[lpennock]

Computer handles it. With that said it is a good idea to use Tow/haul mode when towing or hauling.

 

[AH64ID]

You cannot lug your truck, period. The programming won’t let you.

By definition lugging would be full throttle without any rpm gain, so there doesn’t have to be an associated rpm with it. It is easier to lug at lower rpms thou.

The other thing to remember is that this motor doesn’t operate like your 5.9 did. It has a fair amount more displacement, a variable turbo, and much better and more precise tuning. It can and will run at lower rpms without any issue.

I find tow/haul to be beneficial anytime I’m around 4K lbs heavier than empty.

 

[Ozymandias]

Simple said there is nothing to compare from your old 99 to this 22.
It has still 4 wheels but that's about it...

And the computer takes care of business - you are not able to harm that truck by any means with normal driving.

 

[Turbo Terry]

Good things to know. I used to run a lot in third gear. About 2000 rpm. OD off My DTT shifted into 4 th precisely at 50 mph. Sometimes our highways are to bad here to go very fast and the transmission would lock and unlock a lot. Fast slow frost heave road work etc. But your right a whole different beast. I do like being able to use the gear selector high and low to hold in one gear like say maybe 4 th gear to keep the rpms up but since I can’t really lug the engine what’s the point except maybe a real curvy road or small rolling hills etc to use the exhaust brake better time will tell

 

[Ozymandias]

City driving with lots of speeding up fast and brake hard. Heavy Trailers in hilly Terrain and so much more where you want to keep the rpms up for faster throttle response.

 

[Joseph Donnelly]

Initially, I was suspicious of the 3.42 differential ratio and the low rpms the engine tended to run. These new design 6.7s do very well at lower rpm's than our old 5.9s.

 

[Cummins12V98]

Initially, I was suspicious of the 3.42 differential ratio and the low rpms the engine tended to run. These new design 6.7s do very well at lower rpm's than our old 5.9s.

I loved my 3.42's in my 11 DRW HO but the 68rfe in first was not good at taking off on grade with 29k combined. So I went AISIN 4.10's on my 15 DRW. Love the ease of launching on grades now. BUT after driving my Son's 15 SRW AISIN 3.42's towing a combined 28k taking off on grade with ease I wish I had gone with 3.42's even with 34k combined. I have a friend with a 13 Mega DRW with 3.42's towing 34k combined with zero issues with 15k on the clock.

On my 11 I always ran TH to keep the rpm's up in the proper gear for instant acceleration. I know it was not hurting it to run without TH but it felt really sluggish.

 

[Dasmoeturhead]

I think I know what Turbo Terry is saying, or not. Here goes, my new 21 SO 2500 seems like the rpm's are low (1000 rpms) while still in 6th gear in flat ground doing 25 mph. I go from 45 mph to 25 during some tight curves on our rd. While I'm in the turn my truck seems to be lugging. I always have to step on the accelerator pedal to get it to shift down. It makes me feel better. The truck will just motor up the hill without doing that , but it just feels like it should have shifted down to 3rd or 4th gear. My 2015 3500 drw with the aisin did the same thing. I guess it's normal, but I don't have to like it. Lol.

 

[lpennock]

Shift to Tow/Haul and it will downshift rather than just staying in the higher gear.

 

[Dasmoeturhead]

Shift to Tow/Haul and it will downshift rather than just staying in the higher gear.

Yeah that will work, and I've done it many times, but it ain't right. I don't like the harsh multiple shifts and the way the EB works at low speed in town while the tow/haul is engaged. Not a deal breaker as I've lived with it for over 6 years. Just letting TURBO TERRY he's not the lone stranger here. If others don't have this problem fine, but I do, and at least one other person does.
It's an automatic, and it should be able to be operated like an automatic. I shouldn't have to push buttons, or manually shift. That kind of takes away from the auto experience doesn't it?

 

[AH64ID]

seems like the rpm's are low (1000 rpms) while still in 6th gear in flat ground doing 25 mph.

That seems odd. 6th gear at 25 would be ~600 rpms, not counting torque converter slippage. My Aisin won't shift into 6th, or even 5th, at that speed. 4th is questionable, but would be ~1000 rpms on your truck with 3.73's.

 

[Dasmoeturhead]

Shift to Tow/Haul and it will downshift rather than just staying in the higher gear.

If I do this ^ , while I'm going around one tight curve near home it down shifts to 1st gear while I'm still going 20-25 mph. This isn't right either.

 

[AH64ID]

If I do this ^ , while I'm going around one tight curve near home it down shifts to 1st gear while I'm still going 20-25 mph. This isn't right either.

No, 1st gear isn't right. That's over 3100 rpms, are you sure it's not second?

Are you watching current gears on the EVIC? Or just guessing at the gear?

 

[Turbo Terry]

I will try towhaul mode

 

[Dasmoeturhead]

That seems odd. 6th gear at 25 would be ~600 rpms, not counting torque converter slippage. My Aisin won't shift into 6th, or even 5th, at that speed. 4th is questionable, but would be ~1000 rpms on your truck with 3.73's.

It could possibly be lower than 1000 rpms but when I going around this curve I also have to keep truck in my lane and not looking down at the rpms or you will get side swiped on this narrow road full of large dump trucks that don't stay in there lane.

 

[AH64ID]

It could possibly be lower than 1000 rpms but when I going around this curve I also have to keep truck in my lane and not looking down at the rpms or you will get side swiped on this narrow road full of large dump trucks that don't stay in there lane.

My point is that 25 is too slow for 6th gear. Are you positive it's in 6th?

 

[Dasmoeturhead]

No, 1st gear isn't right. That's over 3100 rpms, are you sure it's not second
^^^^ exactly
Are you watching current gears on the EVIC? Or just guessing at the gear?

Trying to observe both.

 

[NIsaacs]

Yeah that will work, and I've done it many times, but it ain't right. I don't like the harsh multiple shifts and the way the EB works at low speed in town while the tow/haul is engaged. Not a deal breaker as I've lived with it for over 6 years. Just letting TURBO TERRY he's not the lone stranger here. If others don't have this problem fine, but I do, and at least one other person does.
It's an automatic, and it should be able to be operated like an automatic. I shouldn't have to push buttons, or manually shift. That kind of takes away from the auto experience doesn't it?

If I am not in Tow/Haul, mine does it too. Same with my Ford Escape, I drive in sport mode in town or it lugs along in 6th.

 

[Cummins12V98]

I think I know what Turbo Terry is saying, or not. Here goes, my new 21 SO 2500 seems like the rpm's are low (1000 rpms) while still in 6th gear in flat ground doing 25 mph. I go from 45 mph to 25 during some tight curves on our rd. While I'm in the turn my truck seems to be lugging. I always have to step on the accelerator pedal to get it to shift down. It makes me feel better. The truck will just motor up the hill without doing that , but it just feels like it should have shifted down to 3rd or 4th gear. My 2015 3500 drw with the aisin did the same thing. I guess it's normal, but I don't have to like it. Lol.

Simply push the Tow Haul button!!!