Engine Performance

Engine power got a big boost over the B model, though is still pretty bad.  Top cruise speed at sea-level is 282mph (vs. 276mph for the B model) but the E model also has WEP, adding 15mph more when used, giving a 297mph sprint speed.  Increases in altitude can improve the situation by about 2.5-3mph/1,000ft with a top speed of around 340mph at 15K (350mph with WEP).  Notice how low that altitude is for a top speed, the P-40E is definitely a medium altitude or lower aircraft, it does not perform well at higher altitudes.  Climb rate is pretty good, 3,100ft/minute, not out of class for a lot of rides but use of WEP is very important to maximize climb.  Acceleration is dreadful at any altitude, usually in the bottom 5 of all fighters, so never consider trying to out-accelerate anyone.  Fuel duration is very good, 36 minutes on internal fuel with the option to extend that by another 17 minutes with an external drop tank.  That gives a nice combination for flexibility yet long range, or can conversely be used to take off with less internal fuel and carry a drop tank, enabling you to lighten up quickly.

Firepower

The P-40E is well armed, at least as good as a majority of aircraft in the game.  Three .50 cal machineguns are mounted in tight proximity in each wing, giving a total of six, but with only 235 rounds/gun.  This is a good setup, common to several US aircraft, and provides a reasonable hitting power with easy ballistics and high rate of fire.  Total ammunition load is certainly a bit low, making you conserve your ammunition a bit, but once you have someone in the cross-hairs they are going to quickly know you are there and be concerned.  I'd set your convergence as with any other similar aircraft for consistency sake but whether you set them all to a point, or whether you create a small zone convergence, is up to you.  Consider that in most cases you may have to keep your guns on target a bit longer than if you have been flying a cannon armed bird for a while, the difference is noticable, but if you are used to .50's then you can appreciate their ease of use.  If you can, fire short bursts and short-medium ranges for best effect.

Maneuverability

The P-40E and B models both feel very similar to me though I think the B turns possibly a tiny fraction better (the E model picked up 1,000lbs or weight and no increase in wing area so it would seem reasonable). Overall I tend to think the P-40E is a little more stable for shooting and a bit more pointable, possibly in part due to repositioning the weight of the guns to the wings from the cowl.  You do have to be careful though, it seems the P-40's both have nasty tendancies to enter spins as this is one of the few planes that appears able to "get away" from you if pushed too far.  Flat spins, upright and inverted, are entirely possible and difficult to recover from in the P-40.  Turn-rate seems average, I wouldn't want to push my luck against a good turner but wouldn't be too afraid against a bad one.  Be careful of vertical maneuvering though, someone who ropes you in a climbing turn can be big trouble though you can probably hang in there a lot longer than if you were in the P-40B.  Dive control is excellent though the P-40 starts to suffer a bit in roll above 450mph.  The general controls are pretty heavy at 500mph though right through 550mph there remains enough control authority to recover from most situations pretty easily.  The airframe seems strong to flight stresses though not necessarily to damage from gunfire.

Flying the P-40E

I actually like flying the P-40E from time to time, usually bringing it to a lower-intensity fight or one where I know I can pick my spots a bit better.  In that setting it can be pretty effective and still survive without too much trouble.  Usually you do feel that your pushing yourself a little more though to seal up kills as every mistake you make is amplified slightly so you simply need to fly at a higher quality level.

The biggest issue with the P-40E is lack of engine performance, specifically in speed or ability to replace energy.  This tends to form the basis for the offensive and defensive use of the aircraft.  When flying a P-40E, build up some energy before you enter the fight, either climbing for a while or coming in at the highest cruise speed possible, saving your WEP until you really need it.  The P-40E does get better at medium altitudes so try and start there and work your way down, spending your altitude as you need it.  Get out before you reach the ground, setting a floor value after which you will leave, reposition, and come back.  The P-40E makes a good BnZ'r as it has good ride at most speeds and sufficient firepower to damage aircraft with short shots.  You can't expect instant cannon type performance but knocking off pieces with a good shot can really make the fight easier in the long run.  I wouldn't plan on extended turning fights because they can quickly bleed you out of energy that you can't easily replace.  If you can get a quick situation where you saddle up though that is best, you can usually finish off most aircraft given a reasonable ranged shot with a second or so on target.  Don't waste ammunition though, you don't have a terrific amout and you'd hate to run out when you actually have a quality shot.

Defensively, the P-40E is not a good escaper, for lack of a better term.  You need to get out a little earlier than on some aircraft or never get overcommitted in the first place.  Diving away can be fine as long as you have the altitiude you need and get a good head start.  The P-40E is not a great accelerator, even in a dive, so many aircraft can easily catch you if they start their dives at the same time as you do.  Extreme speed dives are ok, the P-40E can handle just about any speed you can throw at it although the lower you get the less performance you actually have after you've blown your speed.  The P-40E has nice direct handling though so most defensive maneuvers can be reasonably easy to perform at a quality level.  Don't get hung up trying to climb with anyone though or chasing people in the vertical, that tends to leave the P-40E hung out to dry.

Fighting the P-40E

While the P-40E is significantly more dangerous than the B mode, it still can be beaten reasonably easily.  You do have to respect the better climb and firepower of the P-40E though, it can quickly make you pay for being sloppy but could should be considered as only an average or worse performer.

Always try and keep your speed high enough to avoid a P-40E.  That gives you lots of options in the vertical and ways to build separation quickly. Against a majority of planes you are likely to fly, you will still have a 40mph advantage over a P-40E in level flight.  If the P-40E has been engaged in a long fight already there is even a chance that he will be low on WEP and you could have much more.  Climbing up to higher P-40E's is not too difficult though it's usually smart to move away from the battle a bit, climb, then come back.  The P-40E still doesn't tend to have a lot of roaming power to chase people around the sky.  Many P-40 pilots will be a bit impatient though and over-commit to the first attack them make.  A strange issue, a lot of P-40E pilots become frustrated by the longer transit/climb times to get to the fight (and watching everyone around them pass by) so they get over-anxious and immediately dive on the first enemy they see ( usually also having pretty bad tunnel vision).  Try and sneak up on the P-40 is you can, the lack of level speed and a somewhat restricted rear view can make this fairly easy.

If attacked, never give up shots if you can help it.  The icon of the P-40B and E are the same but the P-40E has the same firepower as a P-51D so respect it the same way. Identifying which model you are up against is useful but I'd be sure to respect both models and 90% of the P-40's you meet are likely to be the E model, not the B. Usually you will find P-40's working the edges of the fight and diving in at great speed from higher altitudes.  Avoid and try to move away from them, building as much separation as you can.  P-40's are not good at closing distances unless they have altitude to use for speed.  Try to bleed the P-40 out of energy if you can or use vertical to maintain your own energy.  High speed dives may work but the P-40's in general are excellent divers so can probably follow you given a chance.  Usually the dive can build enough speed to hold separation until low altitudes where your overall advantage in top speed plays out.  Lots of people simply dive away from a P-40 and then extend at low levels and high speeds.  The P-40E can't generally catch you in the dive, though may match you, and once low he is out of options.  Sometimes you can even reverse or zoom climb after allowing the P-40 to slow a bit, then come back as almost an immediate agressor to the fight.  P-40's do tend to draw quite a bit of "easy kill" attention though and often you can find 4 or 5 guys chasing a P-40 rather than chase a Spitfire.