best tuner for 6.7 cummins

5 Best 6.7 Cummins Tuners: Ultimate 2025 Guide Is your 6.7 Cummins feeling a little…sluggish? Like it’s holding back on you, sacrificing performance for the sake of factory settings? You’re not alone. Many Cummins owners crave that extra kick, improved fuel efficiency, and overall enhanced driving experience. And let’s be honest, nobody buys a Cummins…