Cheap tuning box 96 early tdi?

Anybody tried one of the cheap boxes I see on eBay? Maybe even the ones that plug direct to obd port? Just curious of results including mpg

OBD port ones won't work. The other ones basically function as an evry mod. Best to keep it stock, money would be better spent on a set of nozzles to be honest, even with stock boost that will be a more noticeable improvement.

Ok just curious not looking to go nuts just a simple safe upgrade without eating into mpg

Figured I might use euro 110 stuff? I have some euro ecu would that help?

A set of nozzles would be your best bet, the ECU and wiring should remain untouched unless installing chips.