Red Bull says it learned some useful lessons during the period of uncertainty over its engine supply last year.
After falling out with engine supplier Renault, Red Bull explored all other options for a new engine supply deal in 2016. It was designing several different concepts for the RB12 based on the various power unit designs of F1's four manufacturers before settling for another year with Renault under TAG Heuer branding.
"We were looking at other power units, there is no secret to that," Red Bull chief engineering officer Rob Marshall said. "We had a good idea of what requirements those would have on car design so we were looking at various different car design concepts in parallel.
"It's a good exercise because it shows you what the opposition are up to anyway. Some supplied a bit of info, some didn't supply any, but I think we got as good an idea of what everybody is up to on the grid as anyone."
Red Bull managed to negotiate a supply of year-old Ferrari engines for Toro Rosso, but that option was not available to the senior Red Bull team.
"We didn't have that option, the option was closed to us with regard to the one year out of date Ferrari," chief technical officer Adrian Newey said. "Secondly, you are dooming yourself to always be some way behind and I believe I am not allowed to refer to who makes the power unit these days, but our power unit manufacturer are on a good course now."