Under the right conditions more weight is bad, under other conditions more weight is good. The contact patch of the HummerEv tires is large enough I do not think you will see a huge difference between say a TRX, and the Hummer EV. If I was going out in soft mud, I might install wider/taller tires. One thing about the Hummer EV is it should be easier to recover from deep mud than say a TRX, due to the almost flat bottom, where as the TRX would have to pull the axle our of deeper mud than the belly. On the TRX all the projection from the belly pan become plows when you try to pull it out, and give more surface area of resistance. The belly pan of the Hummer was designed such that it should not get hydraulic locked into the mud, but time will tell on that.