Bought a cheap Bluetooth ODB2 dongle, down loaded 'Torque' from android app store. I wanted to check intercooler , boot and vacuum pressures. This is just an observation... I noticed on starting car from cold, vacuum read about -16.1 @ 1120rpm. then when engine settled -23.3 @ 920rpm tick over. In my Mk5 Golf GTI vacuum was always -22 ish regardless from cold or warmed up.