Why United Airlines is the most fuel efficient among the big four

United Airlines has a well-managed fleet. Even with the MAX 10 delays and other MAX disruptions, it has the most fuel-efficient fleet among the big four US airlines. We must provide evidence to support this statement, so here we go. Domestic Single Aisles [caption id="attachment_83721" align="aligncenter" width="513"] DoT T2; AirInsight[/caption] United's previously simple fleet has become complex. In 2010, only a third of the flights were on Boeing aircraft, but by year-end 2023, that had risen to 72%. This is a significant swing. But while there were only two Airbus models (A319, A320) in the mix, there are now eight Boeing models. While this complexity has downsides, the Boeing models can be summed into the 757, 737NG, and 737 MAX. The move to the MAX should see the NGs retired along with the Airbus models. Of course, we will see a new Airbus A321NX fleet growing to replace the 757s and also MAX 10 that were to be delivered. Crucially, though, United has seen excellent improvement in fuel burn. [caption id="attachment_83722" align="aligncenter" width="458"] DoT T2; AirInsight[/caption] United has seen big changes in its domestic operations, such as shorter flights. Notice also the vastly improved fuel burn. Here is another chart that lays out the improved fuel burn at United. [caption id="attachment_83724" align="aligncenter" width="425"] DoT T2; AirInsight[/caption] Here, we see how United's single-aisle fleet is evolving; this insight is crucial. [caption id="attachment_83725" align="aligncenter" width="447"] DoT T2; AirInsight[/caption] This last chart clearly shows how United is upgauging. It is clear why the MAX 10 delay is such a bother. Load factors are strong, and being able to carry more passengers with a limited pilot pool means good revenues. However, the lack of the right aircraft hurts, so we see pilot layoffs. The A321NX is a solution, but a) it is not coming in sufficient volumes, and b) it has too much weight/range. We can see United needs a ~180-seater for a ~1,200-mile range. Within that range/payload mix is what United needs - i.e., a MAX 10. Going for the A321NX means having the payload but having much more range than needed. A final example of MAX's excellent fuel is seen below in our ESG model. [caption id="attachment_83727" align="aligncenter" width="406"] DoT T2; AirInsight[/caption] The MAX is lighter than its A320 equivalent - it's as simple as that. The rest is physics; lighter aircraft are more fuel-efficient. Which reaffirms the level of frustration at United with the MAX 10 delays. Twin Aisles This segment covers all flying, domestic and international. United has been a consistent Boeing customer and only deploys its aircraft in this segment. There is a much delayed A350 order that is dubious at this stage. [caption id="attachment_83736" align="aligncenter" width="518"] DoT T2; AirInsight[/caption] United has steadily updated this fleet, focusing on the 787. It is the only US airline flying the 787-10. As we will demonstrate, that choice turned out to have been a great decision for United. The following chart illustrates how the airline improves fuel efficiency even as it flies longer stages. The airline added service to South Africa and continues to surpass its only competitor in that market, Delta. [caption id="attachment_83737" align="aligncenter" width="457"] DoT T2; AirInsight[/caption] The following chart underscores United's impressive fuel efficiency. After the pandemic, the airline recovered quickly as it moved back into several international markets. That includes new markets, like South Africa. [caption id="attachment_83738" align="aligncenter" width="430"] DoT T2; AirInsight[/caption] The following chart shows impressive synergies between load factors and average seat counts. United recovered and improved fuel burn on slightly fewer seats per flight. [caption id="attachment_83739" align="aligncenter" width="446"] DoT T2; AirInsight[/caption] We mentioned the 787-10 as a good move by United, and here is why we say that. The 787-10 offers market-leading fuel efficiencies. It does not have the range of the -8 or -9, but that works fine for the markets it flies. Moreover, if we look at the 777-200 and -300 numbers, we see that where United can substitute those with the 787-10, saving significant fuel costs. And it does so while also coming at much better numbers than competitor aircraft. [caption id="attachment_83740" align="aligncenter" width="410"] DoT T2; AirInsight[/caption] Summary We offer two tables, first for the industry and then for United. [caption id="attachment_83741" align="aligncenter" width="580"] DoT T2; AirInsight[/caption] Here are the tables for United Airlines. [caption id="attachment_83742" align="aligncenter" width="580"] DoT T2; AirInsight[/caption] The key takeaway is that United needs to keep updating its single-aisle fleet. The need to get MAX deliveries is quite clear. Regarding twin aisles, the 787-10 is doing very well, and more will help as they replace aging 777s and 767s. The upshot of these tables and data is that we believe United has the best fuel efficiency among the big four US airlines. Here is our closing evidence: [caption id="attachment_83748" align="aligncenter" width="580"] DoT T2; AirInsight[/caption] Stage-adjusted, United flies longer routes and delivers top-tier fuel burn. We ascribe this to the MAX among single aisles and the 787 among twin aisles.

US Flight Planner - US DoT On-Time Data	Airbus vs Boeing - Official OEM Data
US Airline Schedule Performance - US DoT Data	Daily OEM Production & Deliveries -

Subscribe To Our Newsletter

Related News

Subscribe To Our Newsletter

Related News

Boeing’s Orders & Deliveries June 2026

Alaska’s Hawaiian Merger: What Form 41 Reveals

WestJet Sources 13 MAX10s From ACG