Merc 320 cdi 2004

[howardm]

Fitted a ,"tuneit device" about 6 mths ago .Happy with the results having put on level 6 . Just come back from York to M/c av 37mpg and engine very smooth thru the gears and alot quicker ..much better than before. BUT engine seems more noisy thru the gears until cruising at 40mph .The car is regularly serviced but not at Merc dealers...stopped going after 2yrs of bad service and excessive costs.

Anyone got experience of this devise ...good or bad or suggestions as to what may cause noisier engine other than the upgrade

thanks