Supreme Diesel
Performance & Injection

SDPI is a diesel performance company built around one thing: making working trucks run the way their owners need them to. Founded and run by Braxton Gravett, SDPI grew out of years of hands-on diesel work — building, breaking, diagnosing and fixing the same platforms we now calibrate.

Today SDPI focuses on two things. First, custom calibration: tune files built one truck at a time across HP Tuners, EZ Lynk, EFI Live, Calterm, WinFlash/SIS, bench BIN work and WinOLS — from Power Stroke, Duramax and Cummins pickups to on-highway trucks and equipment. Every file is matched to your VIN, your calibration number, your hard parts and how you use the truck.

Second, the parts to back it up: exhaust systems, fuel system upgrades, turbos, transmission hard parts and the supporting pieces that make a combination live — the same parts we'd run ourselves.

No call centers, no canned files, no guesswork. When you order from SDPI you're dealing with the person who builds your calibration.