I have a Golf SW and an A6 TDI (2016). I am a mileage freak like some of you but care less about my 0-60 time. Sure we all love Torgue but I would take MPG as my main priority. Will any of the modifications out there give me a significant boost in MPG? Kerma says it will provide me "Significant MPG increases" but would not commit to giving me amounts or a percent increase. Sure, driving habits matter. My A6 in Colorado averages 25-29 in the city and 33-39 on the highway. Occasionally 40-43 with a tailwind on I-80 at 75 MPH. Realistically the averages stay in the 32-34 range. I almost think a new A4 gasser would be close. Need some help in improving my MPG.