not worth the price it seems, the fuel efficiency you gain from it is offset by the stupid costs and hassles! wanted to do it but seems like no point.
'14 Black F11 530xd - NOW
'07 Silver E86 Z4 Coupe 3.0si - SOLD '16
'07 Blue E90 325i - SOLD '12
'06 Silver E90 320d - SOLD '10
'98 Blue E36 320i - SOLD '06