The box says .8mm which is .0314 inches. Even the Bosch spark plug web site says not to change the gap on a multi ground plug. I couldn't even fit my gap tool into it since it is a side fire and the ground tab is rounded to match the electrode.

 

So that's basically 0.032" (stock). So with the amount of boost your pushing, the whole 0.028" gap for chipped 1.8T's seems to be unnecissary.

Sorry to thread jack OP.

 

With a normal spark plug it can be gapped between .032 and .028. Always best to run as much gap as possible, then close it slightly if you end up having spark blow out issues.