Marcof - You can't catch the Me 109G-10 or the Fw 190D-9. They are faster than you until you get really high. Obviously Ta 152 and Me 262 will outperform you too.
Don't count on outclimbing Spits either, unless you climb at 300 IAS.

It's got a bit of a performance "valley" between 17k and 22k. WEP has no effect on speed in that altitude range.
Never fly it in combat with 100% fuel. Burn off the Aux fuel tank before fighting.
It will get just about anywhere you want to go in the MA on 75% fuel. With drop tanks you can fly to Mars.
Performance charts here:
http://www.hitechcreations.com/models/p51b.html Read this one too, as the stuff about engine settings and limits applies to the B:
http://www.hitechcreations.com/models/p51d.html I use the following engine settings if I need to save fuel:
Climb, or Very Fast Cruise: 46" Hg, 2700 RPM.
Fast Cruise: 36" Hg, 2400 RPM.
Best Fuel Economy: 2000 RPM and manifold pressure set to maintain 205 IAS.
Rockets: The tubes stay on after you fire the rockets so it slows you down, makes the plane climb worse, and gives it a bit of a "wobbly" feel. So I avoid them. But they work just like the rockets on other US planes. Diving attack works best. If you dive to steeply or at a very high speed you'll need to actually aim below the target.
[ 12-13-2001: Message edited by: funkedup ]