Sadly, for as much as i love 4 engined planes, no.
(this in the picture is actually Italian Air Force One)
The A340 was designed, or better, was started to be designed, in a time when ETOPS (extended twin range operation, or engines turn or passengers swim) wasn’t really a thing. The few planes which were granted ETOPS only received the ability to fly on moderate distance routes, and everyone in the industry still thought that long routes over oceans would have kept being a monopoly of 4-engined jets.
The usually conservative ICAO and FAA had a bit of a different thought this time tough. It’s a whole other story how possibly the creation of more generous ETOPS certifications was a political move to favour Boeing…but i’m not discussing it right here.
So the first models, the A340–200 and -300 (which were basically enlarged A330s with two extra engines) enjoyed moderate success, while the rival 777 boomed when entering the market a few years later.
Sales never really picked up…
But Airbus wasn’t quite ready to scrap the project yet, so they went on developing in the late ’90s the -500 and -600.
Stretched fuselages, more powerful engines, a lot more range.
But again, those planes didn’t sell great.
They’re main advantage was reliability, sheer size, range and the fact that there were such few orders for them that booming airlines (Emirates, Etihad, Qatar) all ordered A340s to have them as soon as possibile to sustain their growth.
But those advantages were valid only for a few airlines…and often offset by the less thirstiness of the rival 777–200, -200ER, -300. The introduction in the last decade of the -200LR and -300ER definitely killed the A340.
Now, I’ve finished with the A340 history, and let’s now come to your question…as you might have hinted by what there’s above, the A340–500 isn’t fuel efficient.
[as pointed out in another answer, you have to make a comparison…the A340 is a fuel efficiency champion if you put it up against a 707 or a DC-8…but you have to consider it in its age and against comparable planes]
So, its main rival was the 777–200LR…in fact this variant of the triple-seven stole the A340–500’s crown as longest range airplane on the market in 2006.
It is pretty straight forward to understand: two engines, even if significantly bigger, use less fuel than four engines
The difference isn’t that huge: between 8 and 12.5 % depending on route and load.
But in an era when oil prices were skyrocketing after the wars in the middle east and the general financial crisis in the first decades of the new millenium…if airlines needed a ultra-long-range plane they went with the 777–200 LR, not an A340–500, and if they wanted “big capacity”, they went for a 777–300 (and later -300ER) instead of an A340–600.
And this is not even putting the A380 and 747 into the picture, mainly because those two are very different: those planes are bigger, heavier and must have 4 engines, and so they use a ton more fuel…but they’re “WORTH IT”: the space they offer on board for sheer amount of seats or money-making bars, showers, fancy premium cabins etc. offsets the higher gas bill.
But the A340 didn’t have any of those perks, it didn’t have that colossal internal space to offer fancy premium amenities…it was a pretty standard plane…just born wrong with 4 engines.
It was a real shame: had the A340 started being designed a couple years later, it would have probably ended up looking a lot like a 777, and would have enjoyed similar, if not greater, success.
The A340 also, contrary to popular believe, wasn’t really a disaster for Airbus: they built around 400 of them, which isn’t a bad number, and the all programme’s costs were after-all split with the A330, which had a huge success. So it wasn’t really a bank breaker.
A340 are still used by the way, but now only in certain situations and mainly by:
– Governments: Air Force One of Italy, Germany, France (maybe former), Thailand, Egypt, Algeria…having 4 engines is safer than having 2, despite all the ETOPS stuff. And if you got a president on board…safety is never too much.
– Airlines that need to start up quickly, look at Air Belgium, or airlines which need planes to lease to fill a gap due to various problems, look to Air New Zealand right now
– Airlines that just need a cheap long range and high capacity plane and that don’t really mind the extra fuel usage cause they don’t fly it so frequently and the low purchase price is enough to offset that extra fuel, like Air Mauritius
– Airlines who inherit the plane from their parent company and use it seldom, so it’s like at point #3…like Edelweiss Air, Eurowings…
I really love the way the A340 looks…just strap on a couple of nice A350 style winglets and i guess it would become one of the best looking planes in the sky.
There’s just something about that 4 engines that will never fade in prestige.