Small notes also F-15E has more powerful engines in is much heavier and flies only with CFT for combat missions.
Also F-15E is the newest it is more attack aircraft than air superiority one. F-15C were covering F-15E in dessert storm that were performing ground attacks.
I want to add a side note, at least IAF Eagles and actually Falcons as well fly with DASH helmet that gives and important edge over usual F-15 also the IAF has upgraded avionics making it nothing like "plain" F-15C - it is basically F-15E in terms of latest modern avionics but F-15C in terms of performance.
CFTs can be removed. The reasons they are left on the plane have nothing to do with the aircraft capabilities. It is 100% because of the assigned mission. I guarantee you that if the need arose for more air defense aircraft, they'd drop the CFTs on the F-15Es and they'd suddenly have the same or better performance than F-15C/D, plus the WSO and targeting pod would add additional capabilities. An F-15E without CFTs isn't that much heavier than an F-15C, more than compensated for by the bigger and more advanced engines and other capabilities. That extra weight is in structural upgrades that make the F-15E extremely durable. Although not intended to do so, a "clean" F-15E can take 12+ Gs without significant damage. My squadron had 2 F-15Es take 12+ Gs and both were flying again within a few weeks after only minor repairs. An F-15C pulling 12 Gs will literally fall apart inflight.
The F-15E is not "more" air to ground and therefore restricted to A/G missions. If configured the same, it has 99.999999% of the air to air capabilities of an F-15C plus A/G capabilities. Their use is entirely mission requirements based, not the capability of the aircraft or its systems. Also, the F-15E can be fairly easily and quickly upgraded with additional capabilities due to the general purpose digital data bus connecting its avionics.
New build F-15Es could be a further leap in capability, both air ot air and air to ground, if necessary. They'd all have the bigger engines and potentially greatly improved avionics, new displays, new hud, and the latest JHMCS helmets. The gen 2 JHMCS helmets may even be able to be installed 2 per plane, vs. the 1 per plane now, due to different positioning sensor technology, but I don't have much info on that beyond what I read in some manufacturer ads...
A new build F-15E would have an extra 10,000 lbs of thrust over an F-15C and only weigh a few thousand pounds more. And it would be vastly superior in terms of avionics. The basic airframe remains a superb and very capable design, and only the billions upon billions of dollars we're pouring into the F-35 program is keeping us from refreshing our F-15C fleet with a few hundred new build F-15s based on the F-15Es currently in production. Call it the "F-15F" or D+ or whatever you like, but the new aircraft would be better than current F-15Cs and would preserve US air to air dominance for another 30 years or more, at half the price of more F-22s or F-35s. And if we suddenly needed more A/G assets, put on the CFTs and suddenly those new air defense F-15Es become full-up nuclear strike capable attack fighters.
Or drop the CFTs on the current F-15E fleet and give them to the guard/reserves for air defense, move one or two switches from the back up to the front cockpit so they can be flown solo, and buy new silent eagle F-15Es for the active duty force in a strike role as they are now, but more survivable in a modern air defense system. That would be really good for overall national defense.
