i like most of you have been considering the many devices available to do this job. The 'genuine' boxs from companies like Dragon are relatively expensive, but they do do the job properly. i was still concerned when i saw the Kingquick boxs on the webb and e-bay as i was worried about my fairly new engine! I rang the company and spoke to Ian, he completely reassured me and as i lived locally he offered to fit it for me.
i was looking mainly for fuel improvement and i mmediately noticed a 10-15% increase, they tell you that you will get 10%. The improved response was amazing, with safer overtaking and a smooth acceleration. I can only tell you that with a 30 day full refund if you are not satisfied and the reasonable price for most engines from £115.00 on e-bay although i had the more expensive version, i cant recomend them enough for diesels. They just plug in by the way so easily removed. just remember to check out the supplier for warranty and refund policy if you dont get any benifit.