FREE TOOL · CONSERVATIVE MULTIPLIERS
Stage 1 / 2 / 3 tuning calculator
Enter your engine's stock figures to estimate realistic Stage 1, Stage 2 and Stage 3 power and torque gains. Multipliers are conservative and based on real-world ECU tuning experience across Bosch EDC15/16/17, MED17, MG1/MD1, and Siemens platforms.
How the multipliers work
Software tuning gain depends almost entirely on the headroom built into the OEM calibration. Diesel turbos run the most conservative factory maps (emissions + warranty), so they get the largest software-only gains. Petrol turbos have less headroom but still respond well. Petrol NA engines barely respond to software alone.
| Engine type | Stage 1 | Stage 2 | Stage 3 |
|---|---|---|---|
| Diesel turbo | +20-30% HP | +35-50% HP (needs intake/DPF off) | +50-80% HP (hardware mods) |
| Petrol turbo | +10-20% HP | +20-35% HP (intake/exhaust) | +35-60% HP (turbo upgrade) |
| Petrol NA | +3-7% HP | +5-12% HP (intake/headers) | +10-20% HP (cams/forced induction) |
These figures assume healthy engine, healthy turbo, clean intake, working DPF/EGR systems (or properly removed/blanked for Stage 2+). A tired turbo or carboned-up intake will limit Stage 1 gains to roughly half the estimate.
Stage definitions used here
- Stage 1 — Software-only on stock hardware. Boost, fueling and timing maps re-optimised within OEM safety margins.
- Stage 2 — Software + supporting hardware: high-flow intake, downpipe, sometimes intercooler upgrade. EGR / DPF off may be required for diesel.
- Stage 3 — Bigger turbo, upgraded fuel system, full exhaust, and a Stage 3 calibration written specifically for the hardware combo. Often requires injector upgrades and reinforced internals at the high end.