Airlines burn a lot of fuel. Fuel typically accounts for ~45% of operating expenses and is closely matched by pilot costs. The following chart from Form 41 illustrates just big these two costs are. US airlines have a great record of improving fuel burn.
Let’s start with recent industry history starting in 2015. Regional jets have seen a steady decline in seat miles/gallon, while twin-aisle aircraft have bounced back from the pandemic. What is interesting to see is that single-aisle aircraft saw a steady improvement over the period. This is primarily driven by US airlines deploying MAX and NEO models. The poorer performance among regional jets is most likely a function of that industry’s ongoing struggle with tightening markets and a worsening business environment.
Looking at the industry fuel burn history from 2000 through 3Q22, we see the following.
Fuel burn per hour is down 17.7% and seat miles/gallon improved 11.9%. Good numbers, but not great given over 20 years of technology improvements. However, when we filter for single-aisles we see that seat mile/gallon improved by 16.4%.Â
The OEMs (aircraft and engines) rightly claim the fastest way to improve fuel burn is to deploy the latest models, and the data 
supports this.
The MAX8 result listed we believe is inaccurate because of a data filing by Southwest –Â which are pleased to say is being reviewed by the airline. The MAX 8 numbers should approximate those of the A320neo. The number for 2020 is during the grounding and is best ignored.
There is also a problem with A320neo data because of misfilings by Spirit Airlines.
The E195 numbers reflect EIS into US service via Breeze. Given the small footprint, these numbers are also best treated as preliminary.
That said, the table shows that the latest models have the best fuel burn.
The single-aisle fleet saw a ~3% fuel burn improvement over the period. Unfortunately, the MAX grounding throws off that model’s numbers. If we look only at the A320neo family (excluding Spirit) the fleet has seen a 1.2% improvement. A smaller delta, but noteworthy that these aircraft are all reporting seat miles/gallon over the 100 line.
As US airlines continue their fleet refresh, the fuel numbers can be expected to keep improving.
