Hamilton endured disappointing races in Monaco and Canada but dominated both sessions at Circuit Paul Ricard after Mercedes fitted both their cars, plus customer teams Williams and Force India, with their second internal combustion engine, turbocharger and MGU-H of the season prior to FP1.
Having held off on bringing their upgrade to the last race in Montreal, the Silver Arrows remained quiet regarding the specification of their engines this weekend. But the news was soon confirmed after the day’s final session, and Ricciardo is wary of the threat they pose in the French Grand Prix on Sunday.
“I thought we were relatively fast, but then we saw the time of Lewis and the long runs were a bit more up and down. We have a bit of work to do tonight but it wasn't a bad Friday actually,” he said.
“The time to Lewis in this session (FP2) now was a bit too big, but actually our day was pretty productive. Obviously Lewis was pretty quick (so) that’s a bit of a shame, he obviously did a good lap.
“Hopefully they used it (the new engine) today. If they’re going to go quicker, then it looks like everyone is chasing them this weekend. I guess for them it’s working. I don’t know where Valtteri (Bottas) was but obviously Lewis’ time was pretty fast.”
While aware of the improved performance of Mercedes, Ricciardo would rather focus on the job in hand at Red Bull and believes they can have a positive weekend.
“I think we can keep improving. Today was a good day to get a lot of information. I think the downforce level is a question mark. Maybe we have a look and change that. I think it was a good Friday so hopefully it will be a better weekend.
“I think (we can learn) quite a bit. Across cars we changed a few things for this afternoon so I think we got a good bit of data to look at between myself and Max (Verstappen) to try and figure out a direction.
“Downforce levels is a big one, so that’s probably one of the big things we will assess tonight to try and learn which way is better.”
Ricciardo will be after a positive performance on Sunday as he looks to keep his hopes of a maiden F1 world championship alive. He currently sits fourth in the standings, 37 points behind leader Sebastian Vettel.