BMW 5 Series (E39) 1995-2003 520i 150bhp remap figures
Thinking of remapping a BMW 5 Series 520i 150bhp? The standard car makes 150bhp and 190Nm; with a Stage 1 remap from our Leicester workshop we expect around 165bhp and 208Nm, up to +15bhp and +18Nm.
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 | 150 bhp | 165 bhp | +15 bhp |
| Torque | 190 Nm | 208 Nm | +18 Nm |
All maps at a glance
| Map | Power | Torque | Expected gain, up to |
|---|---|---|---|
| Stock | 150 bhp | 190 Nm | |
| Stage 1Maximum software-only performance | 165 bhp | 208 Nm | +15 bhp +18 Nm |
| Stage 1 EcoPerformance with economy in mind | 161 bhp | 207 Nm | +11 bhp +17 Nm |
| Eco mapEconomy first | 160 bhp | 206 Nm | +10 bhp +16 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.
The ECU recorded for this variant is a Siemens MS41/42. Older engine management is simpler to work with, but age matters: worn sensors, leaks and tired components can hold back what a remap delivers, which is why we run a diagnostic check first.
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 150bhp?
We expect 165bhp and 208Nm against 150bhp and 190Nm as standard: up to +15bhp and +18Nm. 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 150bhp?
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: 161bhp and 207Nm expected. The Eco map is economy first: 160bhp and 206Nm. Both still sit above the standard 150bhp and 190Nm.
Do I need to tell my insurer about a remap?
Yes. A remap is a modification, so you should declare it to your insurer.