Also if you are in a DOG fight try to use energy management, meaning do a manouver by pulling up, bring one of your wing's down @ the same time when you slow down decrease your RPM/MAP and as soon as you pull the plane over into the dive increase your RPM/MAP and speed up, this way you are not that easy to shot down rather then fly one continuous climb on high RPM/MAP settings and slowly lose speed and the efficiency of your radiators, and never let the radiators shut.
And no matter what you do, if you do that kind of dogfight against a 109 its only a matter of time until your down, use the weight of your Mustang to gain speed and run.