I needed a bit more power from my 100 BHP Mondeo engine to pull a caravan so decided to fit the Blue Spark Unit. With the unit fitted the engine pulls more effectively and from lower in the rev range. I have also noticed an improvement in fuel economy. The unit couldn't be easier to fit and came with comprehensive instructions including tips on how to get the best out of it. The guys at CR Tech are extremely helpful. I ordered the unit in the afternoon and it was delivered the following morning. Having used the unit for several weeks I can say that it was money well spent and would recommend this product without reservation.