My friend's Supra hits 2bar with 116 leaded...

 

My Michelins run consistently at about 3 bar. I have four of
them too. Does that make 12?

 

Exactly right, Joe.

The boost meter in the dash reports "gauge boost" which is the excess over atmospheric. 1700 h Pa is 0.7 Bar "gauge boost".

 

I thought something was wrong too when I first tried to figure out Porsche's graph. I'm no expert on this one, but it appears they are measuring boost created by the turbos/motor above 1 atmosphere as the base level -- so 1600 equates to the engine producing .6 bar rather than 1.6 bar. At least, that's what I recall being told when first trying to read this graph. I'm sure I'm doing a terrible job explaining this, so we need some of our "scientist" members to jump in here and help me out.