We have updated data on fuel burn and offer this periodic model refresh. Subscribers can access and work with the model. Fuel burn accounts for nearly half of airline operating costs and remains a focus for our analyses. It is also a perennial issue for the industry at large. Our sources are US DoT and Skailark. We cannot create the same charts because these two sources do not have identical metrics. However, we can get close enough to confirm trends. Let's start with the US DoT datasets. Here, we use the T2 data, which extracts data from their T-100. [caption id="attachment_84251" align="aligncenter" width="580"] DoT; AirInsight[/caption] The upper charts look at fuel per aircraft mile. We placed the competitive models together. We want to see the curves descend as that is a positive trend. The curves decline over time, showing improved fuel burn. We know that Spirit Airlines misreports its CEO and NEO data from previous analyses and audits. Therefore, we removed their data from the Airbus charts. We will maintain this until we are satisfied they have fixed their reporting. The MAX 8 and A320neo are very competitive. The A320neo shows slightly better seat miles/gallon because, in the US, it is operated by ULCCs with high seat counts. US-based ULCCs have not yet operated the MAX 8. Allegiant is coming. The MAX 9 and A321neo charts are more interesting. Notice these models have flatter fuel burn curves. The generally accepted thinking is that the A321neo should have better fuel burn because it has more seats and flies longer stages. But no. Alaska is the most influential MAX 9 operator. That airline has such a low fuel burn that it helps rate the MAX 9 as the "greenest" single-aisle in US service. Looking at seat miles/gallon, we see that the A321neo is slightly ahead of the MAX 9. This is the expected outcome and suggests that Alaska is using its MAX 9s particularly effectively regarding stage lengths. After all, the A321neo is used across the Atlantic by JetBlue, and Hawaiian uses it for some long stages. Now, on to Skailark's dataset. Skailark's data covers more airlines and offers better coverage as a result. Here is an example of how useful their data is when looking at the MAX 9 fuel burn. Notice the Alaska result. Only Icelandair is getting a lower fuel burn because it flies longer stages. Skailark's data offers useful symmetry. Here's another example of Southwest Airlines. Even though the datasets are different, we see consistent outcomes. The combination of sources provides compelling insight into the fuel burn issue. Using a different chart style, we see the same competitive models' fuel burn. The blue sparklines report the data trend, and the red triangles are high points for each curve. As we saw with the DoT data, Skailark also shows the A320neo and MAX8 are tightly competitive. There's hardly any daylight between them. When we compare the A321neo and MAX 9, we see a similar split to the DoT, with the A321neo slightly ahead. Notice that MAX 8 and MAX 9 report the same fuel burn from this source. Because readers may not be familiar with Skailark's data, here are two charts focusing on MAX fuel burn numbers. The green numbers reflect the optimal results, and the total represents an average. Conclusions The A320neo and MAX 8 are equal in fuel burn efficiency. Because of the dense seating, the MAX 8-200 probably offers the best seat-mile/gallon results in this category. However, we cannot verify this until we get Allegiant data, but it looks like a good bet. The A321neo has greater seat capacity and longer-range capability, offering slightly better results. But the MAX 10 would be a better competitor model. We are unsure that the A321neo would deliver better results than the MAX 10. The updated results reflect what we have seen before. Many may overlook an important trend: the longer-range capabilities of the newer models. This allows operators to extract better fuel burn while opening new markets. Examples here would be Icelandair with the MAX and JetBlue with the A321neo.