You wanted to get your feet wet with our single file calibration but are now craving custom features and more power? Not to worry! We can upgrade you from the M838T or M840T Single File Calibration to our feature packed M838T or M840T M-Tuner Calibration Suite at anytime!
*M-Tuner requires a one time only bench procedure which requires the ECU to be sent to M-Engineering HQ.
Disclaimer: You accept responsibility and risks of any tunes and added features by M Engineering. If you are not the end user of the car, you will be solely responsible for notifying the purchaser and/or customer they also accept the responsibility and risks of these and M Engineering is not liable. M Engineering is also not liable for voided warranties due to installation of our products.