At State Line Diesel Performance LLC, we specialize in high-quality diagnostics, repairs, and custom upgrades for diesel trucks and commercial fleets across Rock Hill, South Carolina; Charlotte, North Carolina; and beyond. With over 20 years of hands-on experience and the latest tools and technology, we deliver dependable results that speak for themselves. Whether it’s routine maintenance, major overhauls, or performance tuning, we take pride in getting the job done right — no shortcuts, no excuses. Browse our gallery to view the real results we’ve delivered for drivers and fleet operators, and see why we’re the team you can trust for proven performance, start to finish.
