I loathe Airbus versus Boeing debates. Yes, I hate it with a passion. In online forums, by the time you get to a dozen replies, the hardcore fans (ie: blind believers) start hijacking the topic with marketing gimmicks and junk and both sides try to drown out the facts (because it simply doesn't suit them).
One day, I decided, I had enough! I did a fuel burn comparison between the 737-800(w) and the A320-200 (Both CFM56-5Bs and IAE V2500-A5s). When I post them on 737 vs 320 debates, the comparison would either kill the discussion (because the fanatics have no room to wriggle), or it ends up being a slag-fest of outrageous claims.
Let's look at the comparisons:
Max Capacity Fuel Burn:
Simple, A320 wins on the trip burn, but 737-800 can get more seats in so the fuel burn per seat is lower in this aspect.
180 seat and 165 seat capacity or load fuel burn:
Once you go above 500NM, the IAE powered 320s, win. The CFM powered 320s, starts to win above 600NM.
100 seat load fuel burn
This shows that whilst the A320 would win over 600NM (again), its heavier airframe does penalize fuel burn for the shorter trips.
20-ton payload fuel burn
I did this because airlines do not solely look at cost per seat. Cargo, is an important source of revenue on passenger flights. So a Payload based fuel burn comparison gives an idea on how much profit one can make.
Notice that the IAE powered A320s, now start to win at a mere 300NM trips, whilst the CFM powered ones (again), need 600NM to start getting the edge on the 737-800W.
SO WHICH ONE IS BETTER?
Answer: IT DEPENDS.
If I have an airline operations where my routes are predominantly 350NM or less, in terms of fuel burn alone, I'd be called a fool to start chosing the A320 with CFM56s. If my routes are predominantly over 500NM, again, I'd be called a fool if I choose the 737-800W.
But, we know that it is not that simple. After all, we still see 737-800Ws being churned out from Seattle, and the A320 with CFM engines are still selling well.
If fuel is cheap, by all means, go for the 737-800. If fuel is expensive, the A320 with IAEs do look attractive. The good news is, fuel price is an important factor, but is not the only important factor to consider. Maintenance cost is another major issue. The CFM56s are dirt cheap to maintain in comparison to the IAE V2500s albeit more reliable and durable, but the airframe maintenance costs are very similar between the A320 and the 738. This is also reportedly true for the price of the engines.
Of course, there are a myriad of other factors to consider too. At the end of the day, which one has the edge, could be determined by something as simple as who sneezed at the wrong time during the price negotiations!