I have a 2019 3500 Silverado 6.0 gas. Has anyone used a tuner like a “5 star tune “ ? I was wondering if or how they work before I purchase one and which brand I should buy? Thanks
OEM's calibrate for variety of conditions. Tuners take out the "safety" tolerance. Some do a good job, others, not so much. I knew of a guy who did mobile tuning. People LOVED his results, but just about every engine he tuned, eventually grenaded.
I've have and had tuners, but won't put one on the truck I use for towing.
WRT shifting, transmission is looking to put the transmission in the correct gear for the conditions.