Custom ECU Tune for Mercedes M273 V8 – E550, CLS550, CL550, S550, SL550

M273 Custom ECU Tune + Bolt-Ons Up to +40 HP | Sharper throttle • Stronger mid-range • Refined V8 feel Build Your Package: 1. Intake Filter ⬜ No Filter (Tune Only) ⬜ K&N Drop-In Filter ⬜ High-Flow (AFE / BMC) 2. X-Pipe ⬜ No X-Pipe ⬜ Add High-Flow X-Pipe (+$389) 3. Headers ⬜ No Headers ⬜ Add Mid-Length Headers (+$689) ⬜ Add Long Tube Headers (+$899) ✅ All options include the full custom M273 ECU tune + OBD cable + support Choose your add-ons above and add the complete package to cart M273 5.5L V8 Custom ECU Tune The foundation of every build is our bespoke ECU calibration for your M273 V8 — not a generic flash. We refine throttle response, torque delivery, ignition timing, and fueling for a noticeable improvement in real-world driving. What You Can Expect Up to +40 HP / +37 lb-ft on premium fuel Sharpened throttle with reduced delay Stronger mid-range torque for confident acceleration Smoother, more refined power delivery Factory safety systems fully retained Add Selected Filter • X-Pipe • Headers + Custom Tune to Cart → Compatible Vehicles E550 • CLS550 • S550 • CL550 • SL550 • CLK550 How It Works Select your options above and complete purchase We send the OBD cable + read instructions Send us your stock file → receive your custom tune Ready to build your perfect M273 setup?