[Zhukov]

There's no way to fully prove the utility of this mod, because everyone is also resetting their ECU's as part of the process. I don't doubt that some people drive consistent routes so as to let them gauge their mileage pretty accurately, but you can't say if this is just due to the HC filter removal or the ECU reset.

An interesting experiment would be to stick the HC filter back in after the ECU reset, and see if the mileage drops again.