The M133 Engine: A Performance Platform

The M133 is a 2.0-liter turbocharged inline-four engine produced by Mercedes-Benz. It debuted in the 2013 A45 AMG, later appearing in the CLA45 AMG, GLA45 AMG, and other performance models. In stock form, this engine delivers between 355 and 381 horsepower depending on the variant. Its forged internals, direct injection, and twin-scroll turbocharger make it a strong foundation for modifications. Enthusiasts seeking more power often turn to a range of upgrades that can push output well beyond the factory figures. This article covers the realistic cost of upgrading an M133, from $1,500 to $5,000, and what you can expect for your investment.

What Does an M133 Engine Upgrade Cost?

The total price for an M133 upgrade depends heavily on your power goal and the parts chosen. A basic software remap costs around $1,500 and adds 30–50 horsepower. A full top-end build with a hybrid turbo, upgraded fueling, and extensive cooling can exceed $5,000, but also yields gains of 150–200 horsepower. Most enthusiast builds fall in the middle tier ($2,000–$3,500) and include a combination of tuning, bolt-ons, and an intercooler upgrade. Below we break down costs by modification tier.

Tier 1 – Budget Upgrades ($1,500 – $2,000)

Entry-level modifications focus on unlocking the engine’s factory headroom. The most effective is an ECU remap or a piggyback tune. Companies like RENNtech and Eurocharged offer custom tunes that raise boost pressure, adjust timing, and optimize air-fuel ratios. A quality tune costs $1,200–$1,800. Combine it with a drop-in air filter or a high-flow intake (around $300–$500) and you stay under $2,000 while gaining 40–60 horsepower.

Tier 2 – Mid-Range Upgrades ($2,000 – $3,500)

Adding an upgraded intercooler, a performance downpipe, and a cat-back exhaust system puts you in the mid-range. An intercooler upgrade from brands like Wagner Tuning or CSF costs $1,000–$1,500. A downpipe with a high-flow catalytic converter can run $600–$1,000. The exhaust system adds $800–$1,200. When paired with a tune, these parts unlock 70–120 horsepower. Many owners also upgrade the intake manifold or install a larger throttle body, which adds $300–$600 and contributes to better top-end power.

Tier 3 – High-End Upgrades ($3,500 – $5,000+)

For maximum output, you need a larger turbocharger or a hybrid unit, along with supporting fuel system modifications. A hybrid turbo (stock housing with upgraded internals) costs $2,000–$3,500. A full stage 3 kit that includes a turbo, injectors, and a custom tune ranges from $4,000 to $5,000. At this level, the engine can produce 450–500 horsepower, but you’ll also need upgraded charge pipes, a high-flow catalytic converter, and often a water-methanol injection kit. Total cost for a turnkey high-power setup can exceed $5,000, but the results are on par with much larger engines.

Detailed Breakdown of Common M133 Upgrades

Below we cover each major modification and its typical cost and power contribution. Prices include parts only; professional installation can add 20–30% to the total.

ECU Tuning

ECU remapping is the single best value upgrade for the M133. It modifies fuel maps, ignition timing, and boost targets. A stage 1 tune gains 40–50 horsepower and costs $1,200–$1,800. A stage 2 tune (requiring a downpipe) costs $1,500–$2,200 and adds 60–80 horsepower. Many tuners also offer dual-file setups (e.g., 93 octane vs. race fuel) for an extra $200–$400.

Intake and Exhaust

The stock air intake is restrictive. A cold air intake system with a heat shield costs $300–$600 and yields 5–15 horsepower. A turbo-back exhaust system (downpipe + cat-back) costs $1,500–$2,500 and can free up 15–25 horsepower. Choose stainless steel for durability or titanium for weight savings. A muffler delete is cheaper ($200–$400) but may cause drone.

Turbocharger Upgrades

Turbo upgrades range from a simple hybrid compressor wheel to a full billet unit. A hybrid turbo (stock turbine housing with larger compressor) costs $2,000–$3,000 and adds 60–100 horsepower. A full turbo kit including manifold, wastegate, and intake piping costs $3,000–$4,500. High-end offerings from AMR Performance can push the M133 beyond 500 horsepower but require supporting mods like port injection and a larger fuel pump.

Cooling and Fueling

Cooling is critical for sustained power. An upgraded front-mount intercooler costs $1,000–$1,500. A larger radiator ($400–$700) and oil cooler ($500–$800) prevent heat soak during track sessions. On the fuel side, high-flow fuel injectors ($400–$700) and a higher-pressure fuel pump ($600–$1,000) support +100 horsepower increases. Some owners install a water-methanol injection kit ($500–$900) to lower intake temperatures and allow more aggressive timing.

Factors That Affect the Final Price

  • Part Quality: Budget brand parts may cost half of a premium brand, but fitment and durability suffer. Stick with known names like Wagner, AMR, Renntech, or Eurocharged.
  • Labor Costs: A full turbo swap can take 10–15 hours at $100–$150 per hour. Installation costs can add $1,000–$2,000 to your build.
  • Vehicle Platform: The M133 is used in A/CLA/GLA 45 models. CLA and GLA may require additional adapter pipes or different under-tray modifications.
  • Desired Power Gains: The more power you want, the more supporting mods you need. A 400 hp build might cost $3,000, but a reliable 500 hp build can easily exceed $7,000.
  • Warranty and Tuning Philosophy: Some tuners offer warranty-backed tunes that cost more. Others may flash without a license – avoid those to protect your engine.

Real-World Power Gains by Modification Tier

Testing on a dynojet shows typical wheel horsepower (whp) gains for an M133 equipped with a performance tune and bolt-ons. Figures are approximate and vary with fuel quality, altitude, and condition.

  • Base stock: 320–340 whp (depending on model year)
  • Stage 1 (tune only): 360–390 whp – cost $1,500–$2,000
  • Stage 2 (tune + downpipe + intake): 400–430 whp – cost $2,500–$3,500
  • Stage 2+ (add intercooler + exhaust): 430–460 whp – cost $3,500–$4,500
  • Stage 3 (hybrid turbo + fueling + cooling): 460–510 whp – cost $5,000–$7,000+

These gains translate to 1/4-mile times dropping by 0.5–1.2 seconds. A stage 2+ M133 can run low 11-second quarter miles while remaining daily-drivable.

Choosing the Right Parts and Installer

Not all shops understand the M133’s direct-injection system and its heat management challenges. Look for tuners with specific dyno experience on the Mercedes-Benz 2.0 platform. Check forums like MBWorld or BenzWorld for reliable builder recommendations. Avoid generic “off-the-shelf” tunes from unknown companies; they can cause knock or overboost. For parts, buy from specialty retailers such as FCP Euro (to take advantage of their lifetime warranty) or directly from performance brands that support the M133.

If you plan to track the car, prioritize cooling upgrades. An upgraded intercooler and oil cooler are non-negotiable for sustained high-load runs. On the street, a stage 1 tune with a good intake and exhaust provides a satisfying increase without overwhelming the stock brakes or transmission.

Conclusion

The M133 engine responds very well to modifications, and the price range of $1,500 to $5,000 covers everything from a simple tune to a near-500 horsepower monster. Start with an ECU flash and intake if your budget is tight; you’ll notice the difference immediately. For those chasing higher numbers, invest in a quality turbo upgrade and intercooler, and always allocate funds for professional installation and a proper dyno tune. With the right parts and a reputable shop, your M133-powered Mercedes can become a serious performance machine without sacrificing reliability. For more technical details on the M133’s capabilities, refer to Mercedes-Benz’s engine overview.