BMW and Mini engines can be prone to coking up every 40000 miles. The R56 Mini cooper s 2007 onwards is bad for this along with the BMW E90 335i from 2006 onwards. The BMW diesel engines M47, M57, N47, N57. are also bad for excessive carbon in the inlet valves. We have a very powerful walnut blaster to remove the carbon and have the chamber looking like new again. Not only will you see better mpg but you will also see better performance. We have also done mk5 VW golfs. Please contact us for more details.