Four Engines More Maintenance Cost Efficient?

[StrongEagle]

I was reading the Airbus website, dropped over to the A340-600 page (A340-600 aircraft: A340-600 range, specifications (dimensions, seating capacity, performance), cabin | Airbus*| Airbus, a leading aircraft manufacturer (http://www.airbus.com/aircraftfamilies/passengeraircraft/a340family/a340-600/)), and midway down the page the following statement pops up:

In addition, the use of four engines – as opposed to two larger powerplants – allows for a 13 per cent reduction in maintenance costs for operators.

This just doesn't add up for me. If 4 engines create a 13 percent reduction in maintenance costs, then why are the skies filled with large powerplant twins? Does this have something to do with extended/long range flying? If yes, where's the cutoff?

TIA

[Agaricus bisporus]

Try telling that to a BAe146 operator. It is widely thought that it would have been a world beater if it had only had two donks instead of four. Maintenance costs on a small engine aren't greatly different from a larger one so four must surely be far more costly than two?
I wonder what figures Airbus is basing that statement on - sounds like spin to me.

[Denti]

Surely a marketing spin, and one that didn't work out apparently. Those big twins are still produced as fast as possible, the A340 is no longer in production and never sold much anyway.

[Tinstaafl]

Perhaps they're including in their comparison every additional costly bit related to ETOPS maintenance rules that they can find?