One of the things that killed the VC-10 commercially was it's fuel consumption. It was a thirsty beast.
I remember meeting one of my old Argosy colleagues over Gander one night heading east. He was flying from IAD to BZN and I was flying one of Freddie's DC-10s from LAX to LGW. He had 139 passengers on board. I had 345 (plus 15 tons of freight).
Despite the fact that he was 2,000 feet higher than me, he was burning the same amount of fuel.