What changes the towing ability?

Chance Neel · March 5, 2017

I have the 2017 GMC SLT Z71 6.2L with 8 speed. It also has the integrated brake controler and towing package. Why would it only have a tow rating of 6400lbs? That seems like a typo almost.

I'm playing around on GMC's website and right now the 5.3L has a 9.300lb rating in 2x4. Changing that to 4x4 drops it to 9100. The 6.2L 2x4 shows 12,500lbs but the 4x4 drops to 11,200lbs. Selecting the off-road suspension pkg changes the tranny from 3.42 8 speed to a 3.23 and while it won't show me I know that probably drops it some.

I can't really see what the tow rating is after changing from the 3.42 to the 3.23 but how could that possibly cut it's towing almost in half? Even with 3.23, positive traction on, and a warm day it still spins both tires off the line so obviously the power is still there.

So curious what it is that cuts the tow rating so much? With the 8 speed it has such low gearing and so much power already I'm just a little curious. 6,400lbs isn't hard to hit. My Jeep grand cherokee had a higher rating with no integrated brake controller. I probably towed 7000lbs the other day with dirt loaded on a double axle. That's pretty abnormal but was just wondering.

JimCost2014 · March 5, 2017

Must be a typo. 9100 lbs for the 3.23, 11,700 for the 3.42 with 6.2, 8 speed crew cab short box. Just looked it up on Chevrolet.com.

audioworks04 · March 5, 2017

Short explanation is the weakest link in the drivetrain determines max rates tow. This weak link is typically the tranny or transfer case. Sometimes it is as simple as a park lock pin rating.

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Z45 · March 5, 2017

A 4x4 rating is less than a 4x2 because of the added weight of the 4x4 system.

thewhitestallion · March 6, 2017

Where did you see that your vehicle is rated for 6400 lbs?

vranasaurus · March 6, 2017

Are you sure that's not the GVWR?

16LT4 · March 6, 2017

If you can't see what the tow rating is, then how do you know it is being cut in half?

Also, in general, a lot of the reason tow ratings have gone up in recent years is due to the influx of stability control systems, which is why the same truck will have a different tow rating in Canada or the U.S.

I have the 2017 GMC SLT Z71 6.2L with 8 speed. It also has the integrated brake controler and towing package. Why would it only have a tow rating of 6400lbs? That seems like a typo almost.

I'm playing around on GMC's website and right now the 5.3L has a 9.300lb rating in 2x4. Changing that to 4x4 drops it to 9100. The 6.2L 2x4 shows 12,500lbs but the 4x4 drops to 11,200lbs. Selecting the off-road suspension pkg changes the tranny from 3.42 8 speed to a 3.23 and while it won't show me I know that probably drops it some.

I can't really see what the tow rating is after changing from the 3.42 to the 3.23 but how could that possibly cut it's towing almost in half? Even with 3.23, positive traction on, and a warm day it still spins both tires off the line so obviously the power is still there.

So curious what it is that cuts the tow rating so much? With the 8 speed it has such low gearing and so much power already I'm just a little curious. 6,400lbs isn't hard to hit. My Jeep grand cherokee had a higher rating with no integrated brake controller. I probably towed 7000lbs the other day with dirt loaded on a double axle. That's pretty abnormal but was just wondering.