Renault upgrade not powerful enough for Ricciardo

By Alan Baldwin 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. "Last I heard it (the performance improvement) is not massive so from my understanding it's probably not worth taking it." Renault have said the engine is more powerful and efficient but using it would incur grid penalties for Red Bull and