I roll a 2023 AT4x half ton and I recently decided to disable the autostop by way of a Carbyte. This little device sticks on your diag port just north of your hood lever in the cab. It also disables DFM/AFM which wasn't really a selling point for it for me...I just wanted the autostop stopped without pushing the button every time I drove. So a week now into having DFM disabled I have some impressions of being in full v8 mode all the time and I wonder if anyone else here has gone through this. This isn't really an AT4X specific thing obviously. But here we are.
So first impression is that we must be in v6 mode ALOT. Without knowing exactly when cylinders are shut off prior to installing Carbyte, I would have assumed were are always in v8 mode, and then if we get on the highway and set our cruise etc, it might toggle down to v6 and v4 mode if possible. In fact, v8 all the time makes my truck a completely different animal. Accelleration at any speed is faster. I should really do a 0-60 from dead stop with DFM enabled and then disabled for better science, maybe I will when I can get at some non slippery roads (Minnesota winter). I've had to adjust how I step on the gas at a stop light because I've nearly lunged into the car ahead of me a couple of times now. Without any good science, my impression is that I was running in v6 mode almost all the time. And the at4x is now a sports car.
On the topic of mileage, obviously there is a massive swing there. In pure city driving, I barely get above 10mpg. Mixed driving gets me to around 14mpg. And on a long trip where I was able to use the cruise at a modest 65mph, I was at 15.7mpg. Before, those numbers were 12/14/18 mpg respectively. For reference, I have no lift/leveling other than factory. I do have 295/65/r18's on it which is roughly the same height as factory, but 2 cm wider.
Now I really don't care about mileage. When I get a truck, I lift it, put big tires on it, add a grille guard etc...and immediately give up 2-3mpg for the sake of awesomeness. It just so happens this time around I didn't need to do anything to my new truck because it's an AT4x. But it would seem that without DFM/AFM, the 6.2 is almost unusable for most because we go back to 1990's fuel mileage. But I can't stess enough...my truck is now a completely different animal. Anyone else disable DFM and have similar observations?
I actually drive my '24 3500 gas the same way. Towing or not, it's in tow/haul mode. I actually started doing this in '07 when afm/dod became available across all GMs. Yes, probably brings the ole mpg down a little overall, but I'm happy.
