The following chart illustrates that fuel is the highest input cost for airlines. The wild swings in fuel costs play havoc with budgets. Looking at the 2022 published data, we see the following costs for single-aisle aircraft in US service. These aircraft carry most of the US traffic. Across the board. Fuel is the most costly input to flight ops. With that background, let's look at how the US airlines have been doing. Given the crucial fuel cost impact, the following charts illustrate fuel burn per seat/mile to even the playing field. The following charts are laid out similarly, focusing on single aisles. The size of each ball represents the amount of traffic each model carries, the bigger the ball, the more traffic that model carries. The green vertical dashed line is the average stage length for the airline's fleet. The grey horizontal dashed line is the seat/miles/gallon average. The orange horizontal dashed line is 100 seat/miles/gallon - the number the new MAX, NEO, and A220 are achieving or eclipsing. The analysis is based on data reported in the US DoT T-2. Alaska Airlines Retiring the former Virgin America fleet makes sense since fuel numbers for the A320 are not competitive with the rest of the fleet. The 737-700 (73G) fleet is small, and three operate as freighters. The A321neo fleet will retire at the end of 2023. The remaining aircraft group around the same location on the chart. The MAX9 shows significantly improved fuel burn (24.2%) over the 737-900ER. The decision to move to the MAX9 is proving successful at Alaska, offering similar fuel burn numbers to the A321neo. American Airlines Another hybrid fleet from a merger, American's fleet consists of old and new models. The MAX8 has a 24.2% better fuel burn than the 737-800. The A321neo has a 40.5% better fuel burn than the A321s. These numbers are far higher than the OEMs were promising. Note that the newer models operate at longer stages, exploiting their better range capabilities. Delta Air Lines Delta is well-known for keeping older aircraft in service for longer than its peers. The chart shows that is still true, with aging 757s in service. Interstingly, the A320s are the oldest on average at 26.8 years, and date back to Northwest Airlines. The 757-200s average 25.6 years, and the 757-300s average 19.4 years - they are aging fast. The chart shows other aircraft struggling with fuel burn - 717, A319, and A320. Delta is replacing the 757s with A321s and A321neos. The A321 offers 11.5% better fuel burn than the 757-200, and the A321neo offers 29.6% better fuel burn than the A321s. At Delta, only the A321neo operates over the 100-seat/miles/gallon line. We expect the MAX10 to have similar fuel burn numbers to the A321neo. JetBlue Here we have a fleet with no merger impacts. The chart illustrates JetBlue has two models over the 100-seat/mile/gallon line. Their A321neo is delivering 25.2% better fuel burn than the A321s. JetBlue's A220-300s report excellent fuel burn, substantially better than at Delta. United Airlines Here we have another post-merger mixed fleet. The Airbus fleet is legacy United, while many of the older Boeings are legacy Continental Airlines. The Airbus fleet has relatively unattractive numbers. The MAX8 delivers 19.3% better fuel burn than the 737-800. The MAX9 delivers 24% better fuel burn than the 737-900ER. United has several 757s still in service, which MAX10s will likely replace. What about Southwest Airlines, you ask? The data filed with the DoT appears erroneous. Please take a look at the following table that illustrates what we mean. The Southwest data filed with DoT does not appear accurate or even plausible. For comparison, here is the same table for the MAX9 versus the 737-900ER.