I live where it does not get too cold in the winter but cold enough to want some protection. This worked really well with cold starts in the morning. Also, it made my TDI idle smoother.

simply the best diesel additive you can buy, I tried many brands, Optilube, Stanadyne, Power Service and have to tell this is the only one that I can feel the difference, car has more response, runs quieter and my MPG went up by 2-3 MPG

Liqui Moly makes the best quality chemicals.