"We don't really know where we stand going into Austria and of course the car would have been developed. There would have been updates at the first European races at Zandvoort and Barcelona, and there would have been further updates for Montreal" explained Horner.
"So of course all the updates that were in the pipeline prior to the shutdown, plus whatever we've learned subsequent to the shutdown, have been implemented to the car. There are subtle revisions all over the car as part of that update process which I'm sure the other front running teams have also done."
Horner also believes in their new engine supplier, Honda, which is set to start the second year with Red Bull after three victories last year.
"As we head into our second year of our Honda relationship it feels much more integrated within the team. We enjoyed a great debut season with Honda winning three races, and of course now we're looking to build on that. They're ambitious, they share the same ambitions that we do, they've been working tremendously hard during the off-season and of course come into this year with higher expectations" continued the team principal.
"It's a key part of the car and a key partner for us as we move forward and look to mount a challenge for championships in the future."