Vauxhall Astra (H) 2004-2010 1.8 VVT 138bhp remap figures
The Vauxhall Astra 1.8 VVT 138bhp (2004-2010) is a petrol 1.8L model making 138bhp and 175Nm as standard. After a Stage 1 ECU remap we expect 152bhp and 191Nm - up to 14bhp and 16Nm more than stock.
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 | 138 bhp | 152 bhp | +14 bhp |
| Torque | 175 Nm | 191 Nm | +16 Nm |
All maps at a glance
| Map | Power | Torque | Expected gain, up to |
|---|---|---|---|
| Stock | 138 bhp | 175 Nm | |
| Stage 1Maximum software-only performance | 152 bhp | 191 Nm | +14 bhp +16 Nm |
| Stage 1 EcoPerformance with economy in mind | 149 bhp | 190 Nm | +11 bhp +15 Nm |
| Eco mapEconomy first | 147 bhp | 189 Nm | +9 bhp +14 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 Astra
Naturally aspirated petrol engines have no boost to raise, so gains from software alone are more modest than on a turbocharged car and come from fuelling, ignition and throttle response.
The ECU recorded for this variant is a Siemens Simtec 75. 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 Vauxhall Astra 1.8 VVT 138bhp?
We expect 152bhp and 191Nm against 138bhp and 175Nm as standard: up to +14bhp and +16Nm. 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 Vauxhall Astra 1.8 VVT 138bhp?
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: 149bhp and 190Nm expected. The Eco map is economy first: 147bhp and 189Nm. Both still sit above the standard 138bhp and 175Nm.
Do I need to tell my insurer about a remap?
Yes. A remap is a modification, so you should declare it to your insurer.
More Vauxhall Astra figures
Other petrol variants
- 2.0T 168bhp 2004-2010
- 1.6 104bhp 2004-2010
- 1.6 16v Turbo 177bhp 2004-2010
- 1.4 88bhp 2004-2010
- 2.0T 197bhp 2004-2010
- 2.0T VXR 236bhp 2004-2010
All petrol Astra (H) variants · Astra (H) 2004-2010 overview · All Vauxhall figures