How do yo turn the v8 to v4 off?

Question

On a GM v8 that goes to v4 econo mode, is there a way to make it stay in v8 mode?

Answer 1

The only way to get it to turn off is through having it tuned (modifying the programming in the computer). This, in fact, is quite simple, because it is just a checkbox within the code. You deselect it and no more V8 to V4 mode. You can only make the change with specialized equipment and software, though. It's not something you can do through the dash selection menu.

To give you an idea, the equipment cost (software comes with it) for HPTuner's MPVI3 interface is $399 (as of this entry). I have a 2018 Silverado, which has the same V8 to V4 economy mode. I'd then need to license my vehicle through HPTuners to do the tune, which is $49.99/credit. My truck requires four credits, or basically $200 to license it. (I'm betting your Yukon would be similar, depending on the year.) That's nearly $600 just to turn it off. You can possibly find someone in your area which has the hardware/software to do it, but you're going to pay for the license credits as well as their time/knowledge to get it done. A bit cheaper, but not cheap.

My point in this is, you have options, but there's no "easy" way to turn it off.