Jump to content

Terrible highway pulling power

Trent Gonzalez
 Share

Recommended Posts

Trent Gonzalez New Member

Trent Gonzalez

Posted
Posted

2020 GMC Sierra 3500 SRW. 

 

Since brand new, I’ve had terrible pulling power specifically on incline grades (as low as 4%-5%). I routinely haul 5th whee trailer, 10,000-11,000 lbs.
 

Prior to an incline I’m able to maintain 80mph no problem. However, as soon as I hit the incline, the truck bogs down to 65mph and I can’t increase my speed any more, even at full throttle. Truck temperatures are 100% within normal range and temperature has never been an issue. 
 

Truck has a derringer, CAI, and Wehrli Fab intake horn. 
 

No check engine lights so dealership isn’t able to find anything wrong. 
 

These trucks are rated for 21,500lbs so it leaves me stumped why the truck isn’t performing. It has phenomenal low end power, but it just seems to struggle on the highway. Any help would be much appreciated. 

Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted

A Semi is rated for 88K and struggles up inclines. You expect too much. 

It won't do 80 up a 5% grade?

:idiot:

MrGraff Enthusiast

MrGraff

Posted
Posted

If your leaving it on auto shift mode and cruise control on inclines then that's your first problem.  When Im approaching a good incline, I go into manual mode and let the engine get up in rpms or boost and it usually holds speed or increases speed.  That being said, my experience so far towing with the 10spd has been night and day difference vs the old 6 spd.

XY74 Enthusiast

XY74

Posted
Posted

I would look closely at your aftermarket parts and verify nothing is wrong there.  Sounds like it's starving for air.  My trailer is about 9000 lbs and the truck has no trouble with grades at all using the cruise control.  Mine is all stock.  

  • Like 1
  • Thanks 1
Keith_Schumaker Enthusiast

Keith_Schumaker

Posted
Posted

I have a drw, but it has the same running gear so it should have the same power.  My camper is 17k and I am able to keep it at 65 on 5-6% grades,  I haven't tried 80 but I wouldn't doubt that it would be able to as it doesn't struggle at all at 65 even if I have to accelerate a bit to get around a truck on a hill.

Trent Gonzalez New Member

Trent Gonzalez

Posted
  • Author
Posted

Going to try a couple things:

1. New map sensor

2. New fuel filter. 
 

low end power is awesome. Going to rule these two impactful things then go from there. Does truly feel like it’s starving for air and/or fuel. 

  • 1 month later...
2021 HD Enthusiast

2021 HD

Posted
Posted

You are close to 18,000 lbs truck and trailer. You expect it to do close to 100 MPH up hill? If I was pulling that much I would go no were close to that speed. What happens when a moron cuts you off than slams on the breaks? I will tell you dead moron and your truck totaled.

  • 1 month later...
Jrscrib Enthusiast

Jrscrib

Posted
Posted

With the aftermarket parts this is not a surprise as most of them take power and fuel mileage away. I have no problems pulling 16k in mountain terrain 5-7 % with cruise control at 74 mph. Truck is stock and pulls better than my 18 did with same fifth wheel. We have a 9% grade hill that we pull from stop at the bottom and let off for a corner about three quarters of a mile up at 55mph. The ten speed makes a big difference in the pulling on hills. I will say aftermarket intake parts I have seen take power and fuel mileage away on any engine specially on diesels.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,760
    Total Members
    8,960
    Most Online
    MASONV88888888
    Newest Member
    MASONV88888888
    Joined

  • Who's Online   2 Members, 0 Anonymous, 1,343 Guests (See full list)

  • Latest Articles

  • Posts

    • MASONV88888888
      Another 6.2L engine failure!

      By MASONV88888888 · Posted

      My 2025 Silverado 1500 had to receive a brand-new engine (long block) under warranty last month at only around 16,500 miles. Before the replacement, the truck repeatedly displayed "Engine Oil Level Low" warnings, even though the Oil Life Monitor still showed around 50% remaining after about 6,000 miles since my last oil change. After seeing the warning several times, I checked the dipstick with the engine cold, and the oil level was completely normal. The next day, the message escalated to "Add Engine Oil." At first, I assumed it was just a faulty oil level sensor, so I brought the truck to the dealership. After inspecting the engine, they found internal cylinder wall scoring and ultimately replaced the entire long block under warranty. Before this happened, I was planning to install a 4-inch lift and suspension upgrade on my truck. After needing a new engine at just 16,500 miles, I honestly don't see the point anymore. I also contacted GM to ask whether my vehicle qualified for a buyback, but I was informed that it does not at this time. Anyway, this experience has left me with serious concerns about the long-term reliability of this engine. I sincerely hope NHTSA expands the current investigation or recall to include 2025 model and performs a thorough inspection of affected vehicles. My biggest concern is that these engines may fail shortly after the powertrain warranty expires. If GM truly stands behind this engine, then at the very least, please consider extending the powertrain warranty to 10 years for affected owners. That would go a long way toward restoring customer confidence.
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      Without exception but then I'm the odd duck, right? I know what goes into that test, how it is calculated and thus how to beat it. But EPA values are often not beaten by the general public and the government has in past years adjusted the means and methods to come to those values to more closely approximate "Joe Average".    The only real trick to beating that EPA average is don't drive like "Joe Average".    It's the same method you used to profit from "Economic Migration" and in doing so beat the 'stats'. But you, like me, are not "Joe Average".     The thing you don't seem to grasp is this "Purchasing Power Index" isn't forward looking. It doesn't predict what it going to be but looks backward and states what it was. They are not telling us what the THINK, they are telling us what they MEASURED. Example:    Wife says "I'm going to lose 40 pounds by Christmas". May she does, maybe she doesn't but the doctors office who weighed her when she made that statement and again at Christmas only REPORTS what the RESULT was. You and I can banter about what was possible and what aunt Tilly did till the cows come home but the result is the result. Arguing otherwise is.....irrational. That's all I'm saying. This isn't about:      What you are calling a 'Statistic' is a RESULT not a CALCUATION and as a result the RULE. Like gravity as a rule, it can not be broken. 
    • MASONV88888888
      Rattle in the rear!

      By MASONV88888888 · Posted

      Just wanted to say thank you for posting this. Years later, your thread is still helping Silverado owners.   I bought my 2025 Silverado 1500 in January 2025, and I've had what feels like the exact same rattle since day one. After reading your findings, I believe my truck has the same issue with the cable carrier contacting the rear sliding window. To be honest, I had pretty much given up on pursuing the issue. It wasn't until I recently drove another brand's pickup that I realized just how quiet their cabin was—and how noisy mine has been all along. On my truck, the rattle happens on almost any paved road, gets even worse on rougher pavement, and I can even hear it during braking and acceleration.   I actually referenced your thread when submitting my case to GM, hoping they'll recognize this as a recurring issue instead of treating it as an isolated incident. The reason I reached out to GM first is because my dealership told me they would need to keep the truck for at least two days just to diagnose the problem. I was concerned that even after two days, they still might not be able to identify the source of the rattle before giving the truck back to me. I had also asked a few dealerships about this issue during previous service visits, but none of them seemed to know what was causing it or had a solution. That's why I decided to contact GM directly first, hoping they might already have an official repair procedure or guidance for this issue.   I also hope GM eventually comes up with an official fix for this problem. I have a feeling there are many Silverado owners experiencing the same rattle, but most either choose to live with it or simply don't know what the cause is.   Really appreciate you taking the time to document your diagnosis. Your post is still making a difference years later.
    • Buckwild27
      Gas Prices

      By Buckwild27 · Posted

      I have 2 choices. 
    • Grumpy Bear
      Gas Prices

      By Grumpy Bear · Posted

      Do you have access to BP fuels? Some stations have Silver 91 E-0 priced the same as their 93 E-10.  There is a local Marathon with 90 alky free for $6 a gallon but I go down the road to BP for $5-ish. They also have a 100 E-0 but that stuff is $10 a pop. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...