I had to convert your metric units to lb/sq inch, to get an idea
of how "hard" your figures were....dumb American mechanic...

2.0 converts to 28 psi, a figure which is common on many
cars I service. There may be a slight bulge on the bottom of
the tire, but unless the car is filled with lead, it'll look ok.

2.9 converts to 41 psi, which is VERY hard ~ many USA
tires still are limited to 32 psi max cold.

I'd suggest you stop by a repair shop with your gauge, and
ask them to compare its readings to one of their known
accurate gauges ~ it's quite possibly WAY off. I check my
portable gauges frequently against the dial gauge on my
tire machine, and replace them about every year as a
result.

DC3