Towing with a Hummer SUV or Sierra 1500 EV

GM’s large Ultium-powered EVs are impressive vehicles with eye-popping horsepower and torque figures. Another often impressive figure is towing capacity. However, what is it like to tow with an EV? Ewing GMC explains.

Robust Electric Power

Let’s start by looking at the Hummer EV SUV. Looking at the middle of the line, the 3X horsepower is rated at an even 1,000. Torque figures are not published, and some large four-figure and even five-figure numbers have been thrown out there. Motor Trend put their pencils to it and produced a figure of 1,045 lb-ft. That is not peak torque but torque because electric motors have consistent torque from the moment they start moving. It is that abundance of accessible torque that contributes to the Hummer EV SUV 3X’s maximum tow rating of 10,000 pounds.

The GMC Sierra EV Denali Edition 1 has somewhat smaller but still impressive power figures of 754 horsepower and 785 lb-ft of torque, which is higher than any Sierra gas engine while falling short of the 6.6-liter Duramax turbo-diesel with 975 lb-ft of torque. It also has a 10,000-pound maximum towing capacity. It Is also worth noting that, unlike internal combustion engines, electric motors are not impacted by atmospheric pressure changes; the Hummer and Sierra EVs will be just as powerful on the mountaintop as alongside an ocean beach.

Inherent Stability

Of course, towing takes more than power. Stability is another crucial factor, but this also plays to the EV’s advantage, particularly the three-motor system, because the electric motors for each rear wheel can adjust their power output instantaneously based on possible swaying conditions created by the trailer, including during adverse weather or an uneven surface.

The Hummer SUV and Sierra EV also include a towing assistance package. This package features a driving mode specifically for towing that optimizes all systems for the task. The package also includes an air suspension that will keep the vehicle level regardless of cabin or trailer load.

Also included is a rearview camera system with a clear view of the hitch area and trailer guidelines to simplify hitching. The blind-spot monitoring system can extend to cover the length of the trailer, enhancing situational awareness for safer lane changes and turns.

How Far Can You Go?

Gas is very dense in energy. So much so that the Sierra EV’s relatively huge 205 kWh battery stores about the same amount of energy as six gallons of gas. Yet it can travel approximately 400 miles from that. Despite all the improvements in fuel efficiency over the past 50 years, gas engines are only about 20 – 30% energy efficient. That is to say of every dollar you spend on gas, only 20- 30 cents worth actually moves the vehicle. The rest is lost mostly to heat and mechanical drag from the transmission and the rest of the drivetrain. EVs, on the other hand, are 80-90% energy efficient. So, for every dollar spent on electricity, 80-90 cents goes to moving the vehicle.

Trailers are a triple whammy when it comes to efficiency. They add weight, rolling resistance, and aerodynamic drag. The trailer will add the same loss of efficiency for gas or battery-powered vehicles, but it just adds a bit to the massive inefficiency gas engines already have for which they contain big tanks of energy-rich gasoline to accommodate it. For EVs, however, the trailer adds a large amount of inefficiency to a very efficient system, and thus, the impact is greater. Consequently, an EV can still tow a trailer more efficiently than an equivalent gas-powered truck, but the range is more impacted.

Consumer Reports tested the range of EV vehicles while towing. The test did not include either the Sierra EV or the Hummer SUV, but when towing a 10,000-pound trailer, the range of both the Ford F-150 Lightning and Rivian R1T dropped to about a third of their normal range. The more powerful Sierra EV and Hummer SUV may not be as impacted; of course, this is the maximum trailer weight. Lighter trailers will have less impact.

The Sierra EV and Hummer EV also benefit from an 800-volt electrical architecture that allows them to travel up to 100 miles in 10 minutes using a fast 350 kW charger. With towing, that figure could come down to 40 – 60 miles per 10 minutes, depending on the trailer weight.

To sum up, if you have a favorite place not far from home to which you like to bring a boat, camper, or toybox, the Sierra EV and Hummer SUV could possibly be the most competent towing vehicles you have ever had. Longer trips will involve more downtime for recharging, but of course, it will all be 100% emission-free. Since our recreational towing activities often get us closer to the outdoors, it is good to know that we are keeping them clean.

To see how the Sierra EV or Hummer EV can fit your life, visit Ewing GMC and test drive these sophisticated EV models.