Two weeks ago, I used Cataclean (for the first time), and since then, I have noticed a drop in my MPG. My average MPG used to be above 50, and now it’s between 38 and 40.

I checked my air and fuel filter—both are clean, as I changed them two months ago.

I used an OBD2 scanner and found no error codes. There are no dashboard alerts either.

Has anyone experienced a similar issue after using Cataclean?

What could cause high fuel consumption? Any suggestions?

Edited 15 January15 Jan by huzz93

This member has noticed an increase in fuel consumption. Has your weather / temperatures been much lower than normal, and the same or lower than last winter?

The weather has been cold for the last two weeks, though I don't think that alone can make such a huge difference.

Cold weather is perfectly fine with a TDI or TSI if the trips are long enough and oil & coolant and engine up to temp and then running lights, heating etc hardly matters, the average mpg might be little different driving far enough. It is how cold and very short trips that makes quite a difference for plenty of people.