Jaguar XK8 (X100) 1996-2005 4.2 300bhp remap figures
The Jaguar XK8 4.2 300bhp (1996-2005) is a petrol 4.2L model making 300bhp and 420Nm as standard. After a Stage 1 ECU remap we expect 330bhp and 442Nm - up to 30bhp and 22Nm 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 | 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 XK8
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 Denso engine control unit. 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 Jaguar XK8 4.2 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 XK8 4.2 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 XK8 figures
Other petrol variants
All petrol XK8 (X100) variants · XK8 (X100) 1996-2005 overview · All Jaguar figures