Bit of general info for those who dream about fitting a chip and improving their MPG. The only way of achieving more power and torque is to inject more fuel. If you use the power and torque you use more fuel simples. Around town stop start depending on terrain you WILL use more fuel on a chipped engine. The only fuel saving advantages, maybe a couple of MPG, will come to light in torque lock above 50 MPH on a long steady speed run. Because of the more linear map. Chipping to get 170 BHP and the same torque as a 4.0 litre petrol and using that power and torque causes you to use more fuel. Don't believe the advertising it's bollocks.