A turbo lag reduction system for a compression ignition engine, the engine comprising: an engine housing defining at least one cylinder, an air intake manifold and an exhaust system, each fluidly connected with the at least one cylinder, a turbocharger including a compressor in communication with the air intake manifold and a turbine in communication with the exhaust system, and a primary fuel delivery system for delivering a primary fuel to a combustion chamber of the at least one cylinder; and the turbo lag reduction system comprising: a control system and a secondary fuel delivery system delivering a secondary fuel directly into the exhaust system upstream from the turbine under control of the control system; wherein the control system comprises a programmable controller and is configured such that, in use, secondary fuel is introduced into the exhaust system only as required; the turbo lag reduction system also comprising a forward facing camera and an associated image processing system; characterized in that: the image processing system is configured to process images from the camera to notify the control system that a red traffic light has turned amber or green; and in that the control system is configured to activate the secondary fuel delivery system when the vehicle is stationary at a set of traffic signals, in response to the signals turning from red to amber or green. an engine housing defining at least one cylinder, an air intake manifold and an exhaust system, each fluidly connected with the at least one cylinder, a turbocharger including a compressor in communication with the air intake manifold and a turbine in communication with the exhaust system, and a primary fuel delivery system for delivering a primary fuel to a combustion chamber of the at least one cylinder; and the turbo lag reduction system comprising: a control system and a secondary fuel delivery system delivering a secondary fuel directly into the exhaust system upstream from the turbine under control of the control system; wherein the control system comprises a programmable controller and is configured such that, in use, secondary fuel is introduced into the exhaust system only as required; the turbo lag reduction system also comprising a forward facing camera and an associated image processing system; characterized in that: the image processing system is configured to process images from the camera to notify the control system that a red traffic light has turned amber or green; and in that the control system is configured to activate the secondary fuel delivery system when the vehicle is stationary at a set of traffic signals, in response to the signals turning from red to amber or green. a control system and a secondary fuel delivery system delivering a secondary fuel directly into the exhaust system upstream from the turbine under control of the control system; wherein the control system comprises a programmable controller and is configured such that, in use, secondary fuel is introduced into the exhaust system only as required; the turbo lag reduction system also comprising a forward facing camera and an associated image processing system; characterized in that: the image processing system is configured to process images from the camera to notify the control system that a red traffic light has turned amber or green; and in that the control system is configured to activate the secondary fuel delivery system when the vehicle is stationary at a set of traffic signals, in response to the signals turning from red to amber or green. the image processing system is configured to process images from the camera to notify the control system that a red traffic light has turned amber or green; and in that the control system is configured to activate the secondary fuel delivery system when the vehicle is stationary at a set of traffic signals, in response to the signals turning from red to amber or green.