Stage 1 Remap Power Gains | How Much Power Can a Remap Add?

It’s the question every prospective remapper asks first: how much power will I actually get? The honest answer is that it depends on the engine – but there are some general rules of thumb, and a few specific verified examples we can quote you directly.

The honest answer

A Stage 1 remap on a modern turbocharged engine typically delivers:

• Turbo-petrol – +15-30% more power, +20-30% more torque
• Turbo-diesel – +20-40% more power, +20-35% more torque
• Older naturally-aspirated engines – smaller gains, typically +5-10%

On a modern turbo-diesel like the BMW 320d, VW Golf GTD or Audi A4 2.0 TDI, a Stage 1 remap usually adds 40-60 bhp and 60-100 Nm. On a turbo-petrol like the VW Golf GTI Mk7, it can add 60-80 bhp and 80-100 Nm. The exact figure depends on your engine, your mileage, your fuel quality, the current state of the map, and the headroom the manufacturer left in the calibration.

Real-world examples

We can verify the following typical Stage 1 figures for specific platforms we tune regularly:

• Ford Transit Custom 2.0 TDCi EcoBlue – 105 bhp to 190 bhp, 360 Nm to 460 Nm. +85 bhp and +100 Nm.
• VW Golf GTI Mk7 2.0 TSI – 220 bhp to 300 bhp, 350 Nm to 450 Nm. +80 bhp and +100 Nm.
• Audi A5 3.0 TDI – 286 bhp to 350 bhp, 620 Nm to 750 Nm. +64 bhp and +130 Nm.
• BMW 335d – 313 bhp to 365 bhp, 630 Nm to 710 Nm. +52 bhp and +80 Nm.

Exact figures depend on engine, mileage and condition. Use our vehicle lookup for your vehicle’s estimates.

Petrol vs diesel – what’s different?

Turbo-diesels typically have more Stage 1 headroom than turbo-petrols. Three reasons.

1. Manufacturers underrate more diesel models for marketing and tax-class reasons. A 150 bhp 2.0 TDI is often closer to 180 bhp on the standard turbo, with the file capping the output to 150.
2. Diesel fuel has more energy density per kg, so the same boost target and fuelling produces more torque.
3. Petrol engines have tighter knock control – the ECU is more conservative with ignition timing, and the file has to leave more safety margin. Diesel engines don’t have this constraint.

So a Stage 1 diesel file is often closer to a +35% power gain, while a Stage 1 petrol file is often closer to +20-25%.

The 5 factors that affect your specific gains

1. The specific ECU variant – the same engine in different model years can have very different headroom. The B47 320d in the G20 has tighter emissions calibration than the N47 in the F30, so the same Stage 1 file produces slightly different numbers.
2. Mileage and engine health – a high-mileage engine with tired injectors or a tired turbo won’t hit the same peak figures as a low-mileage example. Our pre-job diagnostic flags this.
3. Fuel quality – standard UK pump diesel is fine for Stage 1. Premium fuels (Shell V-Power, BP Ultimate) allow slightly more aggressive timing.
4. Current software – the manufacturer updates the ECU software multiple times during a model’s life. We check the current software level and tune to it.
5. Hardware condition – a sticky EGR or partially blocked DPF will hold back the figures. We always check before tuning.

How to check your vehicle’s specific gains

Use the Boostcore vehicle gains lookup for an estimated Stage 1 power and torque figure for your specific car. The lookup covers most turbocharged cars and vans we tune regularly across Southampton, Hampshire and the surrounding area.

The figures are estimates based on the typical Stage 1 map for your engine. Final figures depend on the exact ECU variant, the mileage, the condition, and the fuel. We confirm the realistic figures after the pre-job diagnostic, before writing any new software.

Frequently asked questions

Will my car actually hit the figures the lookup shows?

Most cars hit within 5% of the estimate. Some hit a little higher (low-mileage, premium-fuel cars with conservative factory software), some hit a little lower (high-mileage, tired-injector cars). The pre-job diagnostic tells you which side of the band your car will fall on.

Is a Stage 1 file different for each car?

Yes – the same engine in different model years and different ECU variants gets a different file. We don’t load generic maps from a library. The file is written for the specific engine, the specific ECU software level, and the specific goals (power, economy, or balanced).

Can I get a higher Stage 1 figure with better hardware?

Yes – that’s what Stage 2 is. A high-flow downpipe, an uprated intercooler, an intake and (on manuals) a stronger clutch allow the file to push harder. Stage 2 typically delivers +80-110 bhp on top of the standard output.

Check your gains

Use the vehicle gains lookup for an estimated Stage 1 figure for your car, or message us with your registration for a confirmed quote.