McLaren racing director Eric Boullier has calmed fears over the team's early performances in testing ahead of the new Formula One season.
During Tuesday's session in Barcelona, Stoffel Vandoorne completed just 38 laps amid a trio of mechanical failures and the picture was not much brighter 24 hours later.
Fernando Alonso suffered additional problems, although he did complete 57 circuits, before stopping two hours in due to what was identified as an oil leak.
Having struggled badly with Honda engines, accruing just 30 constructors' points last season, McLaren have switched to Renault for 2018.
Alonso did get back out for the final few minutes of testing on Wednesday and Boullier believes McLaren's early teething problems are to be expected.
"It's just testing," he said. "On the tyres, if you look at the lap time, Red Bull did a test this morning, [they] put on new mediums [and then] new softs.
"They are half a second faster only, so there is not much difference because of the tarmac specification and the temperature as well. We have a technical reason why we want to work on the car with these [hypersoft] tyres.
"[Regarding] the car breaking down, it's testing so we have some little issues which we have to fix, but it's just testing. It's part of the process. We are on top of this.
"It's a new partnership with Renault, completely new packaging for the car as well. This is testing. Give us time and it's fine."
Meanwhile, Red Bull and Mercedes continued to impress - Daniel Ricciardo setting an unofficial track record on hypersoft tyres, 0.353 seconds faster than defending champion Lewis Hamilton, who was running on ultrasofts.
|Spurs deserved more from best performance of the season - Pochettino|
|Brown absent from Steelers facility on Monday due to ´personal matter´|
|Toronto´s Bussey given eight-match biting ban|
|Barcelona 4 PSV 0: Marvellous Messi lights up Camp Nou|
|Inter 2 Tottenham 1: Icardi, Vecino complete dramatic late turnaround|
|Allegri, Chiellini defend Costa over spitting ban|
|Firmino only fit enough for bench duty|
|Kovac applauds Sanches ahead of Benfica homecoming|
|Tomlin confirms Steelers WR Brown was absent from facility on Monday|
|Mourinho tells United to follow Federer´s lead amid Young Boys pitch concerns|
|Costa banned for four Serie A matches for spitting|
|PGA Tour announces changes to FedEx Cup Playoffs format|
|Rashford to start against Young Boys, Mourinho confirms|
|Ryder Cup heading to Congressional in 2036|
|I never listen to stupid things - De Gea unconcerned by criticism|
|Aguero trains as Mendy sits out Man City session|
|Lampard fined after accepting improper conduct charge|
|Serie B suspended after Pro Vercelli win appeal|
|Mitchell returns to England as defence coach|
|Brady completes Cornet upset in Guangzhou|
|Lopetegui giving no guarantees to ´fighter´ Navas|
|Di Francesco denies racially abusing Costa|
|Saunders apologises for ´sickening´ online video|
|Tianjin Quanjian 0 Kashima Antlers 3 (0-5 agg): Semi-final spot booked in resounding fashion|
|Madrid cannot live on Ronaldo´s glories, warns Ramos|
|Real Madrid are Champions League favourites, insists Man City coach Arteta|
|Stokes & Hales charged with bringing game into disrepute|
|Stephens slips to Vekic defeat in Tokyo|
|Simeone should teach Griezmann values - Ramos questions Ballon d´Or ambition|
|Arteta ready to step into Guardiola´s shoes after missing out on Arsenal job|
|Naive or scheming - Ozil´s agent slams Kroos, Neuer and Muller|
|Bolton´s Darby forced to retire after Motor Neurone Disease diagnosis|
|Root vows dressing support for Moeen over Ashes abuse claims|
|Madrid more dangerous without Ronaldo - Dani Alves|
|Federer fires ominous Djokovic warning to rivals|
|Arsenal confirm Gazidis departure to Milan|
|Man´s best friend? D´Arcy Short ruled out by dog bite|
|Salah has strong bond with ´friend´ Klopp|
|Mistakes were made in Serena´s US Open row - Federer|
|Burgess wants ´truth to come out´ over lewd video allegations|
|Injury brings premature end to Sharapova´s season|
|The next one´s mine - Griezmann underlines Champions League desire|
|A novice coach and a solar-powered stadium – who are Champions League debutants Young Boys?|
|Free-scoring Liverpool and PSG do battle, Kane eyes elite club - Champions League in Opta numbers|
|Braves fall to Cardinals, still move closer to clinching NL East|
|Mack leads Bears past Seahawks|
|Maradona makes winning start in Mexico|
|Barcelona captaincy has changed Messi, says Bartomeu|
|Lithuania qualify for FIBA World Cup after double-overtime win|
|Yelich makes history with another cycle|
|Silva: PSG, Liverpool have world´s two best attacks|
|It´s like a cow seeing a train – Pochettino uses unusual analogy to talk experience|
|Brady discusses Patriots´ trade for Gordon|
|Bills coach McDermott hasn´t spoken to Davis, says he ´didn´t feel a need´|
|Coutinho can´t explain Barcelona´s Champions League struggles|
|Henderson: Run to final can inspire Liverpool in Champions League|
|Eriksen: Everyone expects Kane to score a hat-trick every game|
|Gruden doesn´t regret decision to trade Mack|
|West Ham confirm Wilshere ankle surgery|
|Hughton hails Murray´s cool head as Brighton fight back again|
|It´s not good enough - Hojbjerg blasts Southampton|
|Patriots sign Josh Gordon from Browns|
|Southampton 2 Brighton and Hove Albion 2: Murray denies Saints after Hojbjerg howitzer|
|Wawrinka ready for Khachanov after battling past Bedene|
|Lozano: Joining Barcelona would be a dream|
|Players can fight for Messi´s shirt if they win, says Van Bommel|
|Kaymer tips Europe for Ryder Cup glory|
|Neymar to face Liverpool, confirms PSG´s Tuchel|
|Jardim backs Ronaldo to beat Griezmann in Ballon d´Or battle|
|Atletico will grow through hard work, says Simeone|