I took my 1997 XK8 to Tuning Lab of Shebbear in Devon today for a rolling road power check. The guys were very helpful and gave the car several power checks to see the BHP and torque figures. I was somewhat surprised that the car only produced 205hp at the wheels at 5800rpm and 262ft.lbs of torque at 3850rpm. Does anyone know if these figures are normal?
The performance of the car seems absolutely fine. The engine and transmission are all in excellent condition. I only took it for information to see what it produces for interest. I'm not going to tune it in any way.
The guys at Tuning Lab are real enthusiasts and were genuinely interested in the XK8. They commented on the stainless exhaust which could possibly affect the back pressure and power. They also said about the Alpha air filter element which could inhibit breathing slightly. If there is anyone with any ideas I would be very pleased to see these.

 

205hp at the wheels sounds about right for a N/A 4.0L with some miles on it.

 

+1. sounds about right for an engine rated at 290 SAE net hp.