Jaguar XK (X150) 2006> 4.2 V8 300bhp remap figures
Stock, this 2006> Jaguar XK petrol (4.2L) produces 300bhp and 420Nm. Our expected figures for a Stage 1 remap are 330bhp and 442Nm, an expected gain of up to 30bhp and 22Nm.
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 | 300 bhp | 330 bhp | +30 bhp |
| Torque | 420 Nm | 442 Nm | +22 Nm |
All maps at a glance
| Map | Power | Torque | Expected gain, up to |
|---|---|---|---|
| Stock | 300 bhp | 420 Nm | |
| Stage 1Maximum software-only performance | 330 bhp | 442 Nm | +30 bhp +22 Nm |
| Stage 1 EcoPerformance with economy in mind | 323 bhp | 440 Nm | +23 bhp +20 Nm |
| Eco mapEconomy first | 320 bhp | 439 Nm | +20 bhp +19 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 XK
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.
Engine management is by a Denso unit. We read the ECU on your car and compare it with the software listed here before any work starts, so you know what to expect before you commit.
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 Jaguar XK 4.2 V8 300bhp?
We expect 330bhp and 442Nm against 300bhp and 420Nm as standard: up to +30bhp and +22Nm. 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 Jaguar XK 4.2 V8 300bhp?
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: 323bhp and 440Nm expected. The Eco map is economy first: 320bhp and 439Nm. Both still sit above the standard 300bhp and 420Nm.
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 Jaguar XK figures
Other petrol variants
All petrol XK (X150) variants · XK (X150) 2006> overview · All Jaguar figures