The biggest obstacle trijets face today is operating costs, primarily fuel efficiency, as a three-engine design almost certainly consumes more fuel than a comparable two-engine design. This also greatly increases the difficulty of marketing a new trijet aircraft today, especially for passenger service. However this was worth the trade-off between 1970 and the 1990s when trijets and twinjets shared engines of similar output, such as when the DC-10, MD-11, Boeing's 767, and Airbus's A300, A310, and A330 were all powered by the General Electric CF6, and the additional power from the third engine gave the DC-10/MD-11 advantages in longer range and/or heavier payload over the A300/A330 twinjet. Since the 1990s, with further advancements in high-bypass turbofan technology, large twinjets have been equipped with purpose-designed engines like the Boeing 777's General Electric GE90, allowing twinjets to perform the same tasks as most trijets and even many quadjets but more efficiently.