The new Hummer EV truck comes from the factory on 35s. We took the truck to Moab, Utah on the Fins-n-Things trail. While the stock setup works in tandem with the height-adjustable air suspension – we had several instances when the onboard air compressor was not available to raise the ride height. How about putting 37s on this truck?
GMC says that the new Hummer EV truck is able to roll on 37-inch tires without any other modifications to the truck’s suspension or body. We had to give it a try. Turns out – it was WAY MORE expensive than we ever imagined. Here is the story.
We have about $2,500 of GM accessories credit that GM gave us for our trouble when our Hummer EV truck originally left us stranded with a software problem. We used this credit to buy four Hummer EV accessory wheels that you see here. We think these wheels look amazing.
Our friends at BFGoodrich provided us with a set of five 37×12.5 KM3 heavy-duty Load Range E tires.
Now it gets interesting because the task is not just to take off the original wheels/tires and mount new ones. The main task is to reprogram the Hummer EV truck to tell it that it’s rolling on 37s and not the original 35s. This will affect the reported speed, odometer reading, range estimate, efficiency estimates, and more.
The Boulder GMC dealer charged us $122.95 for the software update that they did at the dealership and $199.00 to call a GM tech-support line to figure out how to do it. Yikes!
Here is the video that shows the whole process and also how the Hummer drivers on 37s.
Spoiler Alert: there is no tire rubbing that I noticed during the first 20-minute drive and full lock-to-lock turning. The new tires are not noticeably louder than the stock Goodyear Wrangler Territory MT tires.