Force India believes Malaysian GP pit issues masked impressive pace

Both Paul di Resta and Adrian Sutil ultimately had to retire because of the nut system problem.

But the pace they showed before then left team boss Vijay Mallya both delighted as his team's progress and despondent over the cars' retirements.

"It's more than deep disappointment. It's extreme disappointment," he said.

"The cars were quick, very competitive: we were racing Mercedes very comfortably, [were] much quicker than the McLarens, quicker than Lotus I would like to believe.

"So it was really looking good until the wheelnut failed."

Di Resta agreed that a significant points chance had been squandered, though he does not think the Malaysia form will be a one-off.

"I went out and was setting purple times, was very quick, and was making good progress," he said of his pace after his first pit delay.

"I was probably looking at seventh place, without the first stop in which I lost all that time, so it is pretty frustrating given how quick we were over the weekend.

"Wheelnuts can be fixed for China, performance can't be fixed that quickly, and performance has been a big highlight of what we have achieved."