{"title":"M278 Catless Downpipes – E550 \/ CLS550 \u0026 S550","description":"\u003cdiv style=\"max-width: 100%; margin: 0 auto; font-family: Arial, sans-serif; line-height: 1.6; color: #333;\"\u003e\n\u003cp style=\"text-align: center; font-size: 16px; margin: 15px 0;\"\u003e\u003cstrong\u003ePerfect for tuned M278 4.7L V8 Bi-Turbo models\u003c\/strong\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003chr style=\"border: 1px solid #eee; margin: 25px 0;\"\u003e\n\u003ch2 style=\"color: #000; font-size: 24px;\"\u003eWhy These Downpipes?\u003c\/h2\u003e\n\u003cul style=\"font-size: 16px; line-height: 1.8;\"\u003e\n\u003cli\u003e✅ \u003cstrong\u003eTrue catless design\u003c\/strong\u003e – massive reduction in backpressure\u003c\/li\u003e\n\u003cli\u003e✅ \u003cstrong\u003e+18–32 whp \u0026amp; +25–40 wtq\u003c\/strong\u003e (with proper tune)\u003c\/li\u003e\n\u003cli\u003e✅ Aggressive turbo spool + deep, exotic exhaust note\u003c\/li\u003e\n\u003cli\u003e✅ Premium 304 stainless steel, mandrel-bent, TIG welded\u003c\/li\u003e\n\u003cli\u003e✅ 100% bolt-on – no cutting, no CEL on most tunes\u003c\/li\u003e\n\u003cli\u003e✅ Lifetime warranty on welds \u0026amp; materials\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 style=\"color: #000; font-size: 24px; margin-top: 30px;\"\u003eChoose Your Chassis:\u003c\/h2\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; gap: 20px; justify-content: center; margin: 20px 0;\"\u003e\n\u003c!-- Variant 1 --\u003e\n\u003cdiv style=\"background: #f9f9f9; padding: 20px; border-radius: 8px; flex: 1; min-width: 280px; box-shadow: 0 2px 8px rgba(0,0,0,0.1);\"\u003e\n\u003ch3 style=\"margin: 0 0 12px; color: #d32f2f;\"\u003eE550 • CLS550\u003c\/h3\u003e\n\u003cp style=\"margin: 0 0 10px;\"\u003e\u003cstrong\u003e2010–2016\u003c\/strong\u003e W212 E550 • C218 CLS550 • S550 (W221)\u003c\/p\u003e\n\u003cp style=\"color: #666; font-size: 14px;\"\u003eFits all M278 4.6L \u0026amp; 5.5L bi-turbo engines in E\/CLS\/S-Class.\u003c\/p\u003e\n\u003ca style=\"background: #000; color: #fff; padding: 10px 20px; text-decoration: none; border-radius: 4px; display: inline-block; margin-top: 10px; font-weight: bold;\" href=\"#\"\u003eShop E550 \/ CLS550 Downpipes →\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c!-- Variant 2 --\u003e\n\u003cdiv style=\"background: #f9f9f9; padding: 20px; border-radius: 8px; flex: 1; min-width: 280px; box-shadow: 0 2px 8px rgba(0,0,0,0.1);\"\u003e\n\u003ch3 style=\"margin: 0 0 12px; color: #d32f2f;\"\u003eS550 (W222)\u003c\/h3\u003e\n\u003cp style=\"margin: 0 0 10px;\"\u003e\u003cstrong\u003e2014–2017\u003c\/strong\u003e W222 S550 \/ S550 4Matic\u003c\/p\u003e\n\u003cp style=\"color: #666; font-size: 14px;\"\u003eSpecifically tuned fitment for the longer W222 chassis and revised exhaust routing.\u003c\/p\u003e\n\u003ca style=\"background: #000; color: #fff; padding: 10px 20px; text-decoration: none; border-radius: 4px; display: inline-block; margin-top: 10px; font-weight: bold;\" href=\"#\"\u003eShop W222 S550 Downpipes →\u003c\/a\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp style=\"text-align: center; font-size: 15px; font-style: italic; margin: 25px 0;\"\u003e“These downpipes woke my E550 up instantly — the turbo spool is addictive and the power is exactly what the tune needed.”\u003cbr\u003e— Mike K. (E550 • 528 whp on E85)\u003c\/p\u003e\n\u003cdiv style=\"text-align: center; margin: 30px 0;\"\u003e\n\u003ca style=\"background: #d32f2f; color: white; padding: 14px 32px; font-size: 18px; font-weight: bold; text-decoration: none; border-radius: 6px; display: inline-block;\" href=\"#\"\u003e 🔥 Browse Both Variants \u0026amp; Add to Cart \u003c\/a\u003e\n\u003cp style=\"margin-top: 15px; font-size: 14px; color: #666;\"\u003eShips same or next business day • Free shipping on orders over $299\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp style=\"text-align: center; font-size: 13px; color: #777;\"\u003eQuestions? Reply to this email or text me directly at [Your Phone].\u003cbr\u003eHappy to help you pick the exact set for your build.\u003c\/p\u003e\n\u003c\/div\u003e","products":[{"product_id":"catless-downpipes-for-w222-mercedes-s550-m278-4-7l-v8-biturbo-2011-2017","title":"Catless Downpipes for Mercedes W222 C217 S550 - M278 4.7L V8 BiTurbo (2011–2017)","description":"\u003cdiv style=\"max-width: 1000px; margin: 0 auto; padding: 22px; font-family: ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif; color: #111; line-height: 1.6;\"\u003e\n\u003c!-- Fitment Badge --\u003e\n\u003cdiv style=\"display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fafafa; margin-bottom: 16px;\"\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eCatless Downpipe Set\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003e\n\u003cstrong\u003eS550\u003c\/strong\u003e • M278 BiTurbo V8 • 2011–2017\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Title --\u003e\n\u003ch2 style=\"margin: 0 0 8px 0; font-size: 22px; letter-spacing: -0.3px;\"\u003e2011–2017 Mercedes-Benz S550 M278 Catless Downpipes\u003cbr\u003e\u003cspan style=\"font-size: 15px; color: #555; font-weight: 500;\"\u003eHigh-flow stainless downpipe set for M278 applications\u003c\/span\u003e\n\u003c\/h2\u003e\n\n\u003cp style=\"margin: 0 0 14px 0; color: #333;\"\u003eReduce exhaust restriction and improve turbo response with a \u003cstrong\u003ecatless downpipe set\u003c\/strong\u003e built for the \u003cstrong\u003e2011–2017 Mercedes-Benz S550 (M278 Bi-turbo V8, W222 sedan \u0026amp; C217 coupe chassis)\u003c\/strong\u003e. Designed to increase exhaust flow for faster spool and stronger mid-range response—especially when paired with proper ECU calibration. Owners commonly report noticeably quicker turbo spool-up and improved throttle response after installation.\u003c\/p\u003e\n\n\u003c!-- Trust \/ What You Get --\u003e\n\u003cdiv style=\"padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff; box-shadow: 0 1px 0 rgba(0,0,0,0.02); margin-bottom: 18px;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eWhat’s Included\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003eComplete left\/right downpipe set (as pictured). Hardware\/gaskets are not included unless shown in photos.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Quick Specs --\u003e\n\u003cdiv style=\"display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 10px; margin-bottom: 18px;\"\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eEngine\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eM278 Bi-Turbo V8\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eChassis\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eS-Class (W222 sedan \u0026amp; C217 coupe)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; padding: 12px 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-size: 12px; color: #666; margin-bottom: 4px;\"\u003eType\u003c\/div\u003e\n\u003cdiv style=\"font-weight: 800;\"\u003eCatless \/ High-Flow\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Benefits --\u003e\n\u003ch3 style=\"margin: 18px 0 8px 0; font-size: 16px;\"\u003eWhy Upgrade the Factory Downpipes?\u003c\/h3\u003e\n\u003cul style=\"margin: 0 0 14px 18px; padding: 0; color: #333;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved exhaust flow:\u003c\/strong\u003e helps reduce backpressure for more efficient turbo operation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSharper response:\u003c\/strong\u003e faster spool and stronger mid-range pull.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMore aggressive sound:\u003c\/strong\u003e increases exhaust volume and tone (varies by setup).\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ECU Tune CTA --\u003e\n\u003cdiv style=\"background: #fff; border: 1px solid #eaeaea; border-radius: 14px; padding: 16px; margin: 16px 0; text-align: center;\"\u003e\n\u003cdiv style=\"font-weight: 900; font-size: 16px; margin: 0 0 6px; color: #111;\"\u003eRecommended Next Step: ECU Tuning\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; color: #555; margin: 0 0 12px;\"\u003eA catless setup may trigger a check engine light without proper ECU calibration or sensor management.\u003c\/div\u003e\n\u003ca href=\"https:\/\/benzunitedparts.com\/products\/custom-ecu-tuning-for-e63-cls63\" style=\"display: inline-block; background: #111; color: #fff; padding: 12px 24px; border-radius: 8px; text-decoration: none; font-weight: 700; font-size: 15px; border: none; box-shadow: 0 2px 4px rgba(0,0,0,0.1); transition: all 0.2s ease;\"\u003eView ECU Tune Options\u003c\/a\u003e\n\u003cdiv style=\"font-size: 12px; color: #777; margin-top: 10px;\"\u003eIf you have a different platform\/tune listing for M278, link this button to that product instead.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Fitment --\u003e\n\u003ch3 style=\"margin: 16px 0 10px 0; font-size: 16px;\"\u003eFitment\u003c\/h3\u003e\n\u003cdiv style=\"border: 1px solid #eaeaea; border-radius: 14px; background: #fff; padding: 12px 14px;\"\u003e\n\u003cul style=\"margin: 0; padding-left: 18px; line-height: 1.7; color: #333;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eMercedes-Benz S550\u003c\/strong\u003e – \u003cstrong\u003e2011–2017\u003c\/strong\u003e (W222 sedan \u0026amp; C217 coupe chassis)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine:\u003c\/strong\u003e M278 twin-turbo V8\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-size: 13px; color: #555; margin-top: 10px; margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eFitment tip:\u003c\/strong\u003e Please confirm your chassis code (W222 or C217) and engine (M278) before ordering. If you’re unsure, message us your VIN (optional) and we’ll help verify compatibility.\u003c\/div\u003e\n\n\u003c!-- Important Notice --\u003e\n\u003cdiv style=\"background: #ffeded; border: 1px solid #f5c2c7; border-radius: 14px; padding: 16px; margin: 18px 0;\"\u003e\n\u003ch3 style=\"margin: 0 0 6px; color: #cc0000; font-size: 18px;\"\u003eImportant Use Notice\u003c\/h3\u003e\n\u003cp style=\"margin: 0; color: #7a1c1c;\"\u003eThis product is intended for off-road or competition use only. Installation may not comply with local emissions regulations and may result in a check engine light without proper tuning.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003c!-- Install \/ Notes --\u003e\n\u003cdiv style=\"background: #fff; border: 1px solid #eaeaea; border-radius: 14px; padding: 16px; margin: 16px 0;\"\u003e\n\u003ch3 style=\"margin: 0 0 8px; font-size: 16px; font-weight: 900;\"\u003eInstallation Notes\u003c\/h3\u003e\n\u003cul style=\"margin: 0; padding-left: 18px; line-height: 1.7; color: #333;\"\u003e\n\u003cli\u003eProfessional installation recommended.\u003c\/li\u003e\n\u003cli\u003eInspect\/replace gaskets and hardware as needed during installation.\u003c\/li\u003e\n\u003cli\u003eRe-check for leaks after initial heat cycles.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003c!-- Shipping \/ Returns --\u003e\n\u003cdiv style=\"margin-top: 18px; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fafafa;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eShipping \u0026amp; Returns\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444;\"\u003eFast shipping. \u003cstrong\u003e30-day returns\u003c\/strong\u003e accepted for unused and uninstalled items in original packaging. Installed\/modified exhaust components are not eligible for return.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c!-- Support --\u003e\n\u003cdiv style=\"margin-top: 18px; padding: 14px 16px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff;\"\u003e\n\u003cdiv style=\"font-weight: 800; margin-bottom: 6px;\"\u003eNeed help confirming fitment?\u003c\/div\u003e\n\u003cdiv style=\"font-size: 14px; color: #444; margin-bottom: 10px;\"\u003eMessage us your VIN (optional) or confirm your year\/model and engine (M278) and we’ll help verify before you order.\u003c\/div\u003e\n\u003ca href=\"mailto:benzunitedparts@gmail.com?subject=2011-2017%20S550%20M278%20Downpipes%20Fitment%20Help\" style=\"display: inline-block; background: #111; color: #fff; padding: 12px 24px; border-radius: 8px; text-decoration: none; font-weight: 700; font-size: 15px; border: none; box-shadow: 0 2px 4px rgba(0,0,0,0.1); transition: all 0.2s ease;\"\u003eContact Us\u003c\/a\u003e\n\u003c\/div\u003e\n\n\u003c!-- FAQ Section - SEO \u0026 ChatGPT Optimized --\u003e\n\u003cdiv style=\"margin-top: 32px; padding: 20px; border: 1px solid #eaeaea; border-radius: 14px; background: #fff;\"\u003e\n\u003ch3 style=\"margin: 0 0 16px 0; font-size: 18px; font-weight: 800;\"\u003eFrequently Asked Questions\u003c\/h3\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWill these catless downpipes fit my 2011-2017 Mercedes S550 on W222 or C217 chassis?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eYes — these M278 catless downpipes are a direct fit for all 2011–2017 S550 models (W222 sedan \u0026amp; C217 coupe chassis) with the M278 bi-turbo 4.7L V8.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eDo I need a tune with S550 M278 catless downpipes?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eHighly recommended. A catless setup will usually trigger a check engine light without proper ECU tuning or O2 sensor spacers.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWhat performance gains can I expect from 2011-2017 S550 downpipes?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eNoticeable improvement in turbo spool, throttle response, and mid-range torque when paired with tuning. Many owners report stronger acceleration and a more responsive feel.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eAre these high-flow downpipes loud?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eThey produce a deeper, more aggressive exhaust note than stock catalytic converters. Sound level depends on your full exhaust setup.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 18px;\"\u003e\n\u003cstrong\u003eWill these work on W222 S550 sedan and C217 S550 Coupe?\u003c\/strong\u003e\n\u003cp style=\"margin: 6px 0 0 0; color: #444;\"\u003eYes. The downpipe set is designed for both the W222 sedan and C217 coupe chassis with the M278 engine.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"BenzUnited Parts","offers":[{"title":"Default Title","offer_id":46717188669615,"sku":null,"price":849.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0631\/8718\/9935\/files\/w222-s63-amg-m157-catless-downpipes-stainless.jpg?v=1772305144"},{"product_id":"2013-2016-mercedes-e550-w212-cls550-c218-m278-rwd-catless-downpipes","title":"M278 Catless Downpipes for Mercedes E550 \/ CLS550 (W212 \/ C218) 2011–2017","description":"\u003cdiv style=\"max-width: 860px; margin: 0 auto; font-family: -apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Arial,sans-serif; line-height: 1.7; color: #222;\"\u003e\n\u003cp style=\"font-size: 16.5px; margin-bottom: 28px;\"\u003eUpgrade your Mercedes M278 BiTurbo V8 with these high-flow \u003cstrong\u003ecatless downpipes\u003c\/strong\u003e. Designed for the 2011–2017 E550 (W212) and CLS550 (C218), they significantly reduce exhaust restriction for faster turbo spool, improved throttle response, and a deeper, more aggressive exhaust note.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eKey Benefits\u003c\/h3\u003e\n\u003cul style=\"line-height: 1.7; padding-left: 20px; margin-bottom: 28px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-flow catless design\u003c\/strong\u003e — Reduces backpressure at the turbo outlets for quicker boost response and stronger mid-range power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect bolt-on fitment\u003c\/strong\u003e — No cutting or modifications required. Replaces factory catalytic converters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRefined AMG exhaust sound\u003c\/strong\u003e — Deeper, more aggressive tone under load with minimal drone during cruising.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImproved turbo spool \u0026amp; throttle feel\u003c\/strong\u003e — Noticeable gains in responsiveness when paired with proper ECU tuning.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eVehicle Compatibility\u003c\/h3\u003e\n\u003cdiv style=\"background: #fafafa; border: 1px solid #eaeaea; border-radius: 12px; padding: 18px 20px; margin-bottom: 24px;\"\u003e\n\u003cstrong\u003eE550 (W212) \u0026amp; CLS550 (C218)\u003c\/strong\u003e\u003cbr\u003e2011–2017 • M278 BiTurbo 4.7L V8\u003c\/div\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eWhat’s Included\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 24px; font-size: 15.5px;\"\u003eComplete left + right downpipe set (as pictured). Hardware and gaskets not included unless shown.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eInstallation Notes\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 24px; font-size: 15.5px;\"\u003eDirect bolt-on replacement. Average install time: 1.5–2.5 hours. Professional installation recommended. Re-check for leaks after initial heat cycles.\u003c\/p\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eRecommended: ECU Tuning\u003c\/h3\u003e\n\u003cp style=\"margin-bottom: 14px; font-size: 15.5px;\"\u003eA catless setup often triggers a check engine light. We highly recommend pairing these downpipes with custom ECU tuning for optimal performance and to clear codes.\u003c\/p\u003e\n\u003cp\u003e\u003ca style=\"display: inline-block; background: #111; color: #fff; padding: 14px 32px; text-decoration: none; border-radius: 8px; font-weight: 600;\" href=\"https:\/\/benzunitedparts.com\/products\/custom-ecu-tuning-for-m278-4-7l-v8-biturbo-e550-cls550-s550-cl550-ml550\"\u003eShop M278 ECU Tuning Options →\u003c\/a\u003e\u003c\/p\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eImportant Use Notice\u003c\/h3\u003e\n\u003cdiv style=\"background: #fff0f0; border: 1px solid #f5c2c7; border-radius: 12px; padding: 18px; margin-bottom: 24px;\"\u003e\n\u003cp style=\"margin: 0; color: #c33;\"\u003eThis product is intended for off-road, track, or competition use only. It may not comply with local emissions regulations and can trigger a check engine light without proper tuning.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"font-size: 19px; margin: 32px 0 12px;\"\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cul style=\"line-height: 1.7; padding-left: 20px; margin-bottom: 24px;\"\u003e\n\u003cli\u003e\n\u003cstrong\u003eWill these fit my 2011–2017 E550 or CLS550?\u003c\/strong\u003e Yes — direct fit for W212 E550 and C218 CLS550 with the M278 BiTurbo V8.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDo I need a tune?\u003c\/strong\u003e Highly recommended. Most owners add ECU tuning to avoid check engine lights and maximize performance gains.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat performance gains can I expect?\u003c\/strong\u003e Faster turbo spool, sharper throttle response, and stronger mid-range torque when paired with tuning.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWill they work with aftermarket exhausts?\u003c\/strong\u003e Yes — designed to work with both factory and aftermarket mid-pipes.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv style=\"margin-top: 40px; text-align: center; font-size: 15px; color: #555;\"\u003e\n\u003cstrong\u003ebenzunited parts • Quality Mercedes \u0026amp; AMG Components\u003c\/strong\u003e\u003cbr\u003eExact item shown • Proudly tested on multiple M278 vehicles • Buyer responsible for final fitment verification\u003c\/div\u003e\n\u003c\/div\u003e","brand":"BenzUnited Parts","offers":[{"title":"Default Title","offer_id":46717236871343,"sku":null,"price":749.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0631\/8718\/9935\/files\/m157-downpipes-mercedes-cls63-w218-closeup.jpg?v=1774837128"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0631\/8718\/9935\/collections\/benzunited-e63-cls63-m157-downpipes.jpg?v=1782464633","url":"https:\/\/benzunitedparts.com\/collections\/m278-catless-downpipes.oembed","provider":"BenzUnited Parts","version":"1.0","type":"link"}