Air Speed Indicator Only Calibrated to 450kias

While I don't now the answer to your question you could press "Ctrl+Z" two or three times and two red lines of information will appear at the top of your screen, KIAS among them.

maybe you could download a different panel that has gaugues that go up to the speed you want. or if you feeling brave maybe just ipmort the gauge from another panel by editing the panl.cfg

P.s I don't want to offend but your not confusing KIAS with TAS?

Thanks Radarman, I'll give that a go and see what happens.

Yes, Spuddi - so far as I know all ASIs are calibrated in kias which I convert to mph when I need to get into a speed I understand.

sri spuddi, I misread your response - what is TAS? Not met that abbreviation.

TAS = True Air Speed. It is indicated airspeed corrected for altitude and temperature. As you gain altitude, becuase of the less dense air, TAS is usually greater than IAS.

as Don Says TAS is the true Airspeed. Alot of people quote this cause its the bigger figure, but it often confuses people cause they think "i'm at 35,000 ft and my airspeed indicater says i'm doing 315knots, i'm sure 747's go faster than this".
theres been loads of discussions on this site about the confusion.
you can even search this site for a way to calculate TAS from KIS given a certain altitude.
Obviously TAS = KIAS on ground level, although if your going to do 315knots at gorund level good luck.

at higher altitudes it's best to go of the mach readings.