For the second race in a row, Lewis Hamilton finished as the on-track runner-up to Max Verstappen - although he was later disqualified from the United States GP for finishing with an overly worn plank.
Last weekend in Mexico City, he climbed from sixth on the grid to trail the Red Bull winner by 14 seconds. Meanwhile, team-mate George Russell rose two places to classify sixth.
While the headline results and strong race pace follow an upgraded floor debuting in Texas, Wolff still reckoned that the Mexico performance could also be attributed to an engine fix.
He reckoned the Brixworth-based High Performance Powertrains site had addressed a lingering turbocharger issue whereby it struggled to breathe and overheated in the thin air at high altitude, as per Mexico City.
Wolff said: “HPP has done a fantastic job over the past few years - that was always our Achilles’ heel here that the turbo didn't breathe good enough.
“That's sorted and it's a strong weekend. Our power unit was like all the others.
“I couldn't be more proud of what HPP has achieved with the power unit.”
Source: Autosport