Disappointed in towing performance

[GearHead71]

And..... Just because the spreadsheet is set up and easy to use now, here's what it would look like if GMC offered the 10 speed in the 6.6 gas.  I don't know why I'm doing this, I'm just getting more disappointed  

 

GMC 2500 6.6L Gas (redline: 5600 RPM)
Diff Gears	3.73
			55 MPH	60 MPH	65 MPH
Gear	Gear Ratio	Final Drive	Engine RPM	Engine RPM	Engine RPM
1st	4.54	16.9342	9907.71	10808.41	11709.11
2nd	2.86	10.6678	6241.421	6808.822	7376.224
3rd	2.06	7.6838	4495.569	4904.257	5312.945
4th	1.72	6.4156	3753.582	4094.816	4436.051
5th	1.48	5.5204	3229.826	3523.447	3817.067
6th	1.26	4.6998	2749.717	2999.691	3249.665
7th	1	3.73	2182.315	2380.707	2579.099
8th	0.85	3.1705	1854.968	2023.601	2192.235
9th	0.68	2.5364	1483.974	1618.881	1753.788
10th	0.63	2.3499	1374.858	1499.846	1624.833

 

 

Problem solved, this would proved TWO additional gears at 60mph.  I'm stuck at 3600 in 3rd.  With the 10 speed, 5th would be 3500, 4th would be 4100 and 3rd would be 4900.  

[Ray Pickle]

Max torque is 4k...if your at 3600 and have no power something is wrong

[rjpoog1989]

Probably just need to go a bit faster to get rpms up.  I know with my 14, 1500, 6.2, 6 speed w/ 3.42 gears seems to be better off at 70mph.  My TT weighs around 5,500lbs and I have no issues with towing it.  I’m am seriously looking at the 6.6 gasser, but not if it’s a downgrade.

[ShotgunZ71]

I’m thinking the OP should keep the engine in the 3500-4000 rpm, regardless of gear needed to do so at a given speed, when towing that same particular incline and see if it performs better. That should keep the engine in its peak band, no matter what gear or speed is needed. Make the engine do what you want it to, not what the computer thinks it should. That should be a good gauge of it’s performance under high stress conditions.

[kenny_r]

Kinda funny how these factors all play out. When they did the new ram 6.4 and 8 speed up the Ike it basically put down the same time as the old 6.0 Silverado...with about 700 extra pounds, not very impressive. The ford with the 10 speed lays down diesel numbers yet barely makes more power than the new 6.6 gas. Seems like the Achilles to the new 6.6 is the gear ratio and trans. I would take the extra 1-2mpg hit in favor of a 4.10 option

[Troy Schultz]

Guys, 

 

I just wanted to chime in, as I just got back from the Colorado mountains towing on my way to Moab.

 

I tow 12,000 trailer  weighed on a CAT scale, that's with my water, firewood, RZR inside the toy hauler, everything, real world weight.

 

I too, found from 2nd to 3rd was way to big of a gap. I was very disjointed. I was either screaming 5,000ish rpm at 50-55 mph, or it would go to 3rd gear then loose speed.

 

Now, I am familiar with the "ike" on TFL, I did do that particular stretch, and if anyone is interested, I was able to hold 50 MPH, in 2nd gear, and my transmission temp got to 239F, and my engine temp did not move. 

 

my whole experience is what brought me to this thread, I was wondering if anyone else had issues going from 2nd to 3rd, and it appears many have. 

[GearHead71]

38 minutes ago, Troy Schultz said:

Guys, 

 

I just wanted to chime in, as I just got back from the Colorado mountains towing on my way to Moab.

 

I tow 12,000 trailer  weighed on a CAT scale, that's with my water, firewood, RZR inside the toy hauler, everything, real world weight.

 

I too, found from 2nd to 3rd was way to big of a gap. I was very disjointed. I was either screaming 5,000ish rpm at 50-55 mph, or it would go to 3rd gear then loose speed.

 

Now, I am familiar with the "ike" on TFL, I did do that particular stretch, and if anyone is interested, I was able to hold 50 MPH, in 2nd gear, and my transmission temp got to 239F, and my engine temp did not move. 

 

my whole experience is what brought me to this thread, I was wondering if anyone else had issues going from 2nd to 3rd, and it appears many have. 

That's the same stretch that I ran into problems.  Speed limit is 60MPH which I couldn't maintain.  Like you, I held about 50 MPH.  What's frustrating is my 2017 RAM 1500 was able to maintain 60 (granted, I was flooring it the whole time.)

[brclark82]

So here is an idea.  I have heard of people having their adjustable pedals set too far back and the accelerator only being 70% or so when they “floor it” thinking they’re 100% throttle.  Try adjusting your pedal forward some and see if you have more travel on your accelerator.  Long shot but it has happened to multiple people. 

Honestly I don’t remember if it was too far forward or too far back causing the problem so just try messing with it some and see if anything changes 

[kenny_r]

That does happen[emoji106][emoji106]

[GearHead71]

39 minutes ago, brclark82 said:

So here is an idea.  I have heard of people having their adjustable pedals set too far back and the accelerator only being 70% or so when they “floor it” thinking they’re 100% throttle.  Try adjusting your pedal forward some and see if you have more travel on your accelerator.  Long shot but it has happened to multiple people. 

Honestly I don’t remember if it was too far forward or too far back causing the problem so just try messing with it some and see if anything changes 

That's a good thought, I didn't know that could be an issue.  Unfortunately I don't have adjustable pedals.  But I'd be interested to hear if that helps anyone else.  

[diyer2]

Not trying to be a smart a$$.

I understand the dilemma you're dealing with.

If you have to be able to tow up IKE at the speed limit you should have got a diesel. 

I have always towed with the mind set that don't abuse the drive train to keep up with traffic or other towing trucks. I find a gear that works for the grade and isn't pushing things to the limit. 

I live in Colorado and have been over IKE many times in lots of different rigs. I will say that most times the speeds were 40-50 mph for gas motors. 

 

[GearHead71]

8 minutes ago, diyer2 said:

Not trying to be a smart a$$.

I understand the dilemma you're dealing with.

If you have to be able to tow up IKE at the speed limit you should have got a diesel. 

I have always towed with the mind set that don't abuse the drive train to keep up with traffic or other towing trucks. I find a gear that works for the grade and isn't pushing things to the limit. 

I live in Colorado and have been over IKE many times in lots of different rigs. I will say that most times the speeds were 40-50 mph for gas motors. 

 

I hear you.  I don't drive it often, but most of the camping we do are up in the mountains. 

 

I didn't want to deal with a diesel.  From what I read if you can answer "yes" to at least 2 of these 3 conditions you should get a diesel:

 

1.  Tow heavy

2.  Tow all the time

3.  Tow at altitude 

 

Really, I can only answer yes to the 3rd.  I guess the only reason I'm disappointed is that I feel like the Ford F250 and RAM 2500 gassers could do it.  I researched the heck out of these trucks before buying but didn't look at this at all.  I figured the powertrain engineers had done their homework.

 

And really the biggest concern for me is I bought this truck to be able to get a larger camper.  Given the struggle with my 5500lb camper I'm not sure I want to go up to a 9500lb one.  I know it will do great everywhere but this one use-case but still.

Edited October 15, 2020 by GearHead71

[diyer2]

I think the issue has been said. Transmission and gearing. GM's fault.

[greatmizzou]

Wonder if there is a software/mechanical bug.

 

Ive not encountered any towing issue related to speed when it comes to towing.  Ive suspected there is an issue with the air/fuel mixture in certain situations.

 

  OP what were the outside weather temps specifically when you felt a loss of power or weak power and in those specific times what octane gas did you run?

[Troy Schultz]

1 hour ago, GearHead71 said:

I hear you.  I don't drive it often, but most of the camping we do are up in the mountains. 

 

I didn't want to deal with a diesel.  From what I read if you can answer "yes" to at least 2 of these 3 conditions you should get a diesel:

 

1.  Tow heavy

2.  Tow all the time

3.  Tow at altitude 

 

Really, I can only answer yes to the 3rd.  I guess the only reason I'm disappointed is that I feel like the Ford F250 and RAM 2500 gassers could do it.  I researched the heck out of these trucks before buying but didn't look at this at all.  I figured the powertrain engineers had done their homework.

 

And really the biggest concern for me is I bought this truck to be able to get a larger camper.  Given the struggle with my 5500lb camper I'm not sure I want to go up to a 9500lb one.  I know it will do great everywhere but this one use-case but still.

 

I can tell you from first hand experience, my 31ft toy hauler weighs 12,500 lbs with the 4-up RZR, water, firewood ect. all weighed on a CAT scale. 

 

It made it up the IKE 50 mph in 2nd gear at 5,000 rpms ... IT CAN DO IT .. you just have to put it to the floor ...