World champion Sebastian Vettel has flown out of southern Spain after a miserable opening two days of running in 2014.
He cancelled his appointments with the media and leapt into his much more reliable Infiniti road car just after lunch.
"At this stage it really makes no difference which driver is sitting in the car," team boss Christian Horner told Germany's Auto Motor und Sport.
Early testing of the all-new V6-powered cars has been fraught, and after getting less than a handful of laps under its belt on Tuesday, Red Bull packed up early on Wednesday with a "Renault energy store problem".
Horner confirmed that sister team Toro Rosso suffered the same problem on Tuesday.
Vettel, on the other hand, managed just 11 laps with the RB10 over his two days, and now hands over to teammate Daniel Ricciardo.
"It was always likely that this (lack of running) was going to be the case," said car designer Adrian Newey, referring to the massive change in regulations since the end of the team's dominant display in 2013.
Newey is known for getting his new cars up and running at the eleventh hour, but even the famous Briton admitted he might have got to work earlier in the second half of last season, when Vettel was in the midst of his nine-race winning streak.
"With hindsight, perhaps in the second half we could have afforded to stop developing the car a little bit sooner," he is quoted by Britain's Sky, "but we weren't to know that at the time.
"So we kept pushing and had less time to work on this year's car."
In this video you can see and hear how bad the engine of the Red Bull RB10 performs: Vettel is testing the Red Bull RB10 on Jerez day.
Unofficial Wednesday test times from Jerez:
1. Jenson Button, McLaren, 1m 24.165s, 43 laps
2. Kimi Raikkonen, Ferrari, 1m 24.812s, 47 laps
3. Valtteri Bottas, Williams, 1m 25.344s, 35 laps
4. Nico Rosberg, Mercedes, 1m 25.588s, 97 laps
5. Sergio Perez, Force India, 1m 28.376s, 37 laps
6. Esteban Gutierrez, Sauber, 1m 33.270s, 53 laps
7. Marcus Ericsson, Caterham, 1m 37.975s, 11 laps
8. Sebastian Vettel, Red Bull, 1m 38.320s, 8 laps