Towards the end of Mark 1 production the Vitesse had nearly as many "luxury" features as the Sterling (for example, electric front seats). There was also a brief run of just over 500 820 Turbo 16v cars using a turbocharged version of the M series developed with help from Tickford, leading to this model often being referred to as the "Tickford Turbo". Utilising such enhancements as sodium-filled exhaust valves and Mahle forged pistons the car produced , although there is much speculation about this figure being severely held back by the electronics as not to step on the toes of the V6-engined models as well as to preserve the reliability of the gearbox.