BMW 5 Series (G30) 2017> 520i (B48B20A) 181bhp remap figures
Thinking of remapping a BMW 5 Series 520i (B48B20A) 181bhp? The standard car makes 181bhp and 290Nm; with a Stage 1 remap from our Leicester workshop we expect around 308bhp and 484Nm, up to +127bhp and +194Nm.
Choose your map
Stage 1 remap figures
A Stage 1 remap is a software-only change to the ECU on an otherwise standard car. It needs no extra parts, which makes it the usual starting point.
| Stock | Vanguard expected | Expected gain, up to | |
|---|---|---|---|
| Power | 181 bhp | 308 bhp | +127 bhp |
| Torque | 290 Nm | 484 Nm | +194 Nm |
All maps at a glance
| Map | Power | Torque | Expected gain, up to |
|---|---|---|---|
| Stock | 181 bhp | 290 Nm | |
| Stage 1Maximum software-only performance | 308 bhp | 484 Nm | +127 bhp +194 Nm |
| Stage 1 EcoPerformance with economy in mind | 276 bhp | 468 Nm | +95 bhp +178 Nm |
| Eco mapEconomy first | 266 bhp | 459 Nm | +85 bhp +169 Nm |
| Stage 2Extra power with supporting parts | 305 bhp | 466 Nm | +124 bhp +176 Nm |
Who is the Stage 1 map for?
- Drivers who want a sharper throttle and a small, honest gain from software alone.
- Owners who would rather keep the car standard in every other way.
- Anyone who wants the fullest software-only map for this engine, accepting that the gain is modest without a turbocharger.
What this means for your 5 Series
Without a turbocharger the improvement comes from ignition, fuelling and throttle mapping rather than boost, so expect a smaller but still noticeable change in response.
This car is listed with a Bosch MG1CS201 engine control unit. Newer ECUs often protect their software, so we read the exact unit and version on the car before confirming the figures on this page.
We remap at our Belgrave Gate workshop in Leicester, or at your home or work within 30 miles, and every job starts with a diagnostic check.
Please note: these are expected figures, not guarantees. Real results vary with the condition of the vehicle, the ECU software version, fuel quality and the hardware fitted. Some options - including Stage 2 and anything that needs extra hardware - are for off-road or competition use only. We check every vehicle first and confirm what is achievable before any work starts.
Figures reviewed 22 October 2026.
Stage 1 questions
How much power does the Stage 1 map give the BMW 5 Series 520i (B48B20A) 181bhp?
We expect 308bhp and 484Nm against 181bhp and 290Nm as standard: up to +127bhp and +194Nm. These are expected figures, and we confirm what is achievable on your own car after a diagnostic check.
Does a Stage 1 remap need any extra parts on the BMW 5 Series 520i (B48B20A) 181bhp?
No. Stage 1 is a software-only change to the ECU on an otherwise standard car.
Is there a gentler map than Stage 1 for this engine?
Yes, two. Stage 1 Eco is performance with economy in mind: 276bhp and 468Nm expected. The Eco map is economy first: 266bhp and 459Nm. Both still sit above the standard 181bhp and 290Nm.
Do I need to tell my insurer about a remap?
Yes. A remap is a modification, so you should declare it to your insurer.