The last two digits of the subvariant of an Airbus plane tells you what type of engine powers that aircraft. Below is every aircraft/engine combo I've photographed!
The second digit tells you the engine type and the third digit tells you the subvariant of that engine. For example the A320-200 has the A320-214 subvariant. The '1' indicates that the plane is powered by the CFM-56. the '4' indicates the specific engine variant is the CFM-56-5B4.
Some type model series only have one engine supplier, like the A220 and A350. The A220 does not have the identifier but the A350 does. There are other notes at the bottom.
A300-605: GE CF6-80C2A5 (GE CF6 variant)
A300-622: PW4158 (PW4000 variant)
A310-304: GE CF6-80C2A2 (GE CF6 variant)
A319-111: CFM56-5B5 (CFM-56 variant)
A319-112: CFM-56-5B6 (CFM-56 variant)
A319-114: CFM-56-5A5 (CFM-56 variant)
A319-131: IAE V2522-A5 (IAE V2500 variant)
A319-132: IAE V2524-A5 (IAE V2500 variant)
A319-133: IAE V2527M-A5 (IAE V2500 variant)
A320-211: CFM-56-5A1 (CFM-56 variant)
A320-212: CFM-56-5A3 (CFM-56 variant)
A320-214: CFM-56-5B4 (CFM-56 variant)
A320-232: IAE V2527-A5 (IAE V2500 variant)
A320-233: IAE V2527E-A5 (IAE V2500 variant)
A320-251N: CFM LEAP-1A26 (A320NEO powered by CFM LEAP-1A variant)
A320-271N: PW1127G-JM (A320NEO powered by PW1000G Geared Turbofan variant)
A321-211: CFM56-5B3 (CFM-56 variant)
A321-231: IAE V2533-A5 (IAE V2500 variant)
A321-251NX(LR): CFM LEAP-1A32 (ACF1 configured A321NEO, hence the 'X', with extra fuel tanks2 to make it an 'LR' powered by CFM LEAP-1A variant)
A321-253N: CFM LEAP-1A33 (A321NEO powered by CFM LEAP-1A)
A321-253NX: CFM LEAP-1A33 (ACF1 configured A321NEO, hence the 'X', powered by CFM LEAP-1A variant)
A321-253NX(LR): CFM LEAP-1A33 (ACF1 configured A321NEO, hence the 'X', with extra fuel tanks2 to make it an 'LR' powered by CFM LEAP-1A variant)
A321-253NY(XLR): CFM LEAP-1A33 (A321XLR3 powered by CFM LEAP-1A variant)
A321-271N: PW1133F-JM (A321NEO powered by PW1000G geared turbofan variant)
A321-271NX: PW1133F-JM (ACF1 configured A321NEO, hence the 'X', powered by PW1000G geared turbofan variant)
A321-271NX(LR): PW1133F-JM (ACF1 configured A321NEO, hence the 'X', with extra fuel tanks2 to make it an 'LR' powered by PW1000G geared turbofan variant)
A330-202: GE CF6-80E1A4 (GE CF6 variant)
A330-223: PW4168A (PW4000 variant)
A330-243: RR Trent 772B (RR Trent 700 series variant)
A330-302: GE CF6-80E1A4 (GE CF6 variant)
A330-302E: GE CF6-80E1A4 (Enhanced variant4 of A330 powered by GE CF6 variant)
A330-303: GE CF6-80E1A3 (GE CF6 variant)
A330-323E: PW4168A (Enhanced variant4 of A330 powered by PW4000 variant)
A330-323X: PW4168A (High gross weight variant5, hence the 'X', powered by PW4000 variant)
A330-343E: RR Trent 7772B (Enhanced variant4 of A330 powered by RR Trent 7000 variant)
A330-343X: RR Trent 7772B (High gross weight variant5, hence the 'X', powered by RR Trent 7000 variant)
A330-941N: RR Trent 7000-72 (A330NEO powered by RR Trent 7000 variant)
A340-312: CFM56-5C3 (CFM-56 variant)
A340-313X: CFM56-5C4 (High gross weight variant5, hence the 'X', powered by CFM-56 variant)
A340-542X: RR Trent 556-61 (High gross weight variant5, hence the 'X', powered by RR Trent 500 variant)
A340-642: RR Trent 556-61 (RR Trent 500 variant)
A340-642X: RR Trent 556-61 (High gross weight variant5, hence the 'X', powered by RR Trent 500 variant)
A350-941: RR Trent XWB-84 (RR Trent XWB variant)
A350-1041: RR Trent XWB-97 (RR Trent XWB variant)
A380-841: RR Trent 970-84 (RR Trent 900 variant)
A380-842: RR Trent 972-84 (RR Trent 900 variant)
A380-861: Engine Alliance GP7270
1ACF: Airbus Cabin Flex is a reconfiguration of the A321 exit doors to accommodate more passengers. All A321NEO's delivered after mid-2018 are in ACF configuration. This configuration is noted with an 'X' in the type model series designation.
2A321LR: The A321LR is not a modification to the A321 airframe. Airlines have the option to replace baggage compartments under the floor with fuel tanks. Airlines can add 1-3 extra tanks. An additional baggage compartment on top of the number of tanks is taken up by plumbing. So if an airline adds 1 extra tank, it takes away 2 baggage compartments and if an airline adds 2 extra tanks, it takes away 3 baggage compartments and etc.
3A321XLR: The A321XLR is a modification to the A321 airframe. The rear center tank extends the wing box aft. The rear center tank takes up luggage space but is more space efficient than the LR's extra tanks, with the wall of the tank being the fuselage itself. The aft extended wing box is the most visible indication that an A321 is an 'XLR' variant.
4Enhanced variants: A330 and A340 enhanced variants feature avionics upgrades including a glass cockpit.
5High gross weight: Longer range variant with higher MTOW, stronger landing gear, and increased fuel capacity. This configuration is noted with an 'X' in the type model series designation.
Engine manufacturers featured:
CFM International, partnership between GE and Safran
Engine Alliance, partnership between GE and PW
General Electric (GE)
International Aero Engines (IAE), partnership between RW, RR, Japanese Aero Engine Corporation, and MTU Aero Engines
Pratt and Whitney (PW)
Rolls Royce (RR)