| Weistec Horsepower | 540 |
| Weistec Torque | 566 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Engine Family | M256 |
| Stock Horsepower | 497 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2026 | Mercedes-Benz | CLE53 AMG | Convertible (A236) | Turbocharged 3L I6 (M256) |
| 2025 | Mercedes-Benz | CLE53 AMG | Convertible (A236) | Turbocharged 3L I6 (M256) |
| 2026 | Mercedes-Benz | CLE53 AMG | Coupe (C236) | Turbocharged 3L I6 (M256) |
| 2025 | Mercedes-Benz | CLE53 AMG | Coupe (C236) | Turbocharged 3L I6 (M256) |
| 2024 | Mercedes-Benz | CLE53 AMG | Coupe (C236) | Turbocharged 3L I6 (M256) |
| 2026 | Mercedes-Benz | GLE53 AMG | Coupe (C167) | Turbocharged 3L I6 (M256) |
| See more | ||||
Product Description
Mercedes-Benz's turbocharged 3.0-liter inline-six is one of the cleverest pieces of engineering AMG has ever adopted wholesale. First introduced under the S-Class before AMG put it to work in the E53, the M256 solves turbo lag with real electrical engineering instead of brute displacement: EQ Boost, a 48-volt integrated starter-generator and electric auxiliary compressor, spools in alongside a twin-scroll turbo to fill torque exactly where a conventional turbo would still be catching its breath. It's a mild-hybrid system, no plug, no meaningful EV range, just a sharp, purposeful low-rpm assist, but it's enough to let AMG run a smaller, more responsive turbo without ever giving up the top end. That architecture has since become the backbone of an entire lineup: E53, GLE53, CLS53, CLE53, and the AMG GT 43/53 4-Door Coupe all run on it.
Weistec's calibration goes to work right inside that electrified turbo system, not around it, recalibrating the ECU's boost, timing, and EQ Boost torque-fill logic. Every OEM protection, knock control, thermal limits, the diagnostics the dealer network relies on, stays fully intact, because this is built to the same rigor as AMG's own calibration work, not bolted on as an aftermarket afterthought. The result speaks for itself: a stock M256's 497 hp and 476 lb-ft climb to 540 hp and 566 lb-ft, taking an already smart piece of engineering and giving it real teeth.
Related Items
How Do You Get Your M256 ECU Tune Tuned?
Follow these steps — this is what your specific vehicle needs and supports.
1
Unlock Check
This ECU requires an unlock first
Modern ECUs are often locked down, especially after a dealer software update, which can block bench flashing or OBD flashing. Our ECU Unlock Service removes those restrictions, is done per ECU, and stays active through most future dealer updates as long as the bootloader isn't overwritten.
Read the full ECU Unlock breakdown →2
Choose Your Tune Stage
3
Core Improvements
Standard with this tune4
Free Add Ons
Want it louder?
This tune can have Burble/Pops added or increased on deceleration, at no additional charge. Select an intensity below and we'll add it to your order, or mention it when requesting your tune — through the Cypher+ app, your calibration request form, or when placing your order.
5
See the full tuning process →
Pick Your Tuning Method
1Selected
Cypher Plus
Order a Cypher Plus and tune your car yourself from your phone, entirely through the MyFlasher app. Watch how it works.
2Selected — Pick return shipping at checkout
Mail It In
Remove your ECU or TCU and mail it to us for tuning. Required for some applications.
3Selected — Pick Will call at checkout
In Person
Bring your vehicle, or just your ECU/TCU, to our Anaheim, CA headquarters. Call 714-202-0005 or email sales@weistec.com to schedule.
4Selected — Order through your local dealer
Cypher Pro Dealer
Visit a certified Cypher Pro Dealer near you. Find one with our dealer locator.
6
Complete The Upgrade
An ECU tune alone won't remove all factory limits or fix how power reaches the ground. Add these to round out the upgrade with no limitations.
Read the full CPC & TCU breakdown →
What is a CPC module?
The CPC (Central Powertrain Control) is a separate control unit that manages things like the active exhaust valves, radiator fan, intercooler pumps, and speed limiter. On many newer Mercedes-Benz vehicles, it also houses torque limiters that can hold back an ECU tune from reaching its full potential.
What is a TCU tune?
A TCU (transmission control unit) tune delivers faster, firmer shifts with higher line pressure, reducing clutch slip and increasing the transmission's torque capacity. It's a worthwhile upgrade on its own, or paired with an ECU tune for a fully sorted powertrain.
Your Total
Good to Know
- This is a reflash of your original module, not a stand-alone unit.
- Power gains vary by vehicle, modifications, fuel, and operating conditions (ambient temperature, altitude, etc.).
- New or upgraded spark plugs are always recommended when tuning.
- Product may not be emissions compliant. Check local laws prior to installation.
- Always use a battery charger during programming.