Renault upgrade not powerful enough for Ricciardo

Formula One - F1 - United States Grand Prix 2015 - Circuit of the Americas, Austin, Texas, United States of America - 22/10/15 Red Bull's Daniel Ricciardo during a press conference ahead of the United States Grand Prix Mandatory Credit: Action Images / Hoch Zwei

AUSTIN, Texas (Reuters) - Renault look like having no takers for their upgraded engine in Sunday's U.S. Grand Prix after Red Bull's Daniel Ricciardo said it did not look enough of a step up and Toro Rosso said they would stick with the old one.

"It's available if we want to use it. Obviously that would mean a penalty, though, so we've got to understand if it's worth it," the Australian told reporters at the Circuit of the Americas on Thursday.