Mercedes-AMG A45 & CLA45 M133 Tuning Guide — Stage 1 to Stage 4 | Power, Cost & Build (2026)
The M133: AMG's Most Underrated Tuning Platform
The Mercedes-AMG M133 is a 2.0-liter turbocharged four-cylinder engine found in the A45, CLA45, and GLA45 AMG models (2013–2019). It was the most powerful series-production four-cylinder engine in the world when it launched — 360 HP in standard form, 381 HP in the facelift — and it responds to tuning with gains you'd normally associate with much larger engines.
The M133 uses a forged crankshaft, lightweight pistons, and a closed-deck block from the factory. The BorgWarner turbo has significant headroom. A proper ECU tune delivers 15–20% power increase from software alone.
Browse all M133 parts: M133 Tuning — A45 / CLA45 / GLA45 complete catalog
Stage 1 — ECU Only
Facelift A45 (381 HP stock): Stage 1: 420–440 HP / 380–400 lb-ft TQ. Gain: +40–60 HP.
Pre-facelift A45 (360 HP stock): Stage 1: 400–420 HP / 370–390 lb-ft TQ. Gain: +40–60 HP.
Stage 2 — ECU + Downpipe
Stage 2 output: approximately 440–460 HP / 400–420 lb-ft TQ. Catless downpipe is mandatory — the single biggest bolt-on for the M133. The A45, CLA45, and GLA45 share the same fitment. Read the full M133 downpipe guide — catless vs 200-cell vs 400-cell for detailed power gains and sound comparisons.
Stage 3 & Stage 4 — Turbo Upgrade
The factory BorgWarner maxes at ~460–470 HP. The YPG Stage 4 turbo upgrade is a direct bolt-on. With Stage 4 turbo, Stage 2 ECU, downpipe, and upgraded intercooler: 500–530 HP. Forged internals are strongly recommended above 500 HP.
M133 Tuning Stages — Comparison
| Stage | Power (HP) | Torque (lb-ft) | Hardware Required | Starting Price |
|---|---|---|---|---|
| Stock (Facelift) | 381 | 350 | — | — |
| Stage 1 — ECU | 420–440 | 380–400 | None | $1,399 |
| Stage 2 — ECU + Downpipe | 440–460 | 400–420 | Catless downpipe | $2,299 |
| Stage 3 — Intercooler | 450–470 | 410–430 | + Race intercooler | $4,499 |
| Stage 4 — Turbo Upgrade | 500–530 | 440–470 | + Race turbo, forged internals | $9,899 |
GCC-Specific Considerations
98 RON is standard across the GCC. The M133's top-mount intercooler heat-soaks quickly in Gulf temperatures — an intercooler upgrade is essential at Stage 2 and above in 40°C+ ambient conditions. GCC-delivered cars do not include GPF; downpipe installation is straightforward.
YPG calibrates all M133 maps for GCC fuel quality and ambient temperatures. See our GCC tuning guides for Kuwait, Saudi Arabia, Qatar, and UAE.
Watch: A45 AMG Stage 2 — Pops and Bangs
Recommended Products
The YPG Process
- Contact YPG via WhatsApp to discuss your build.
- OBD2 flashing hardware shipped worldwide. Free shipping.
- Guided session. 30–45 minutes. Stock file saved. Return-to-stock included free.