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.
|U.S. Open final-round timeline: How clinical Koepka kept his crown|
|Koepka fights off challengers to successfully defend U.S. Open title|
|´Aching´ Neymar urges referees to intervene|
|BREAKING NEWS: Koepka holds on to defend U.S. Open title|
|Lozano goal causes artificial earthquake in Mexico|
|Djokovic: Mental battle will be Murray´s biggest|
|Hummels criticises Germany tactics in Mexico loss|
|Brazil the latest favourites to stumble, but Tite and Neymar won´t panic|
|Magnificent Fleetwood matches U.S. Open record with closing 63|
|Brazil 1 Switzerland 1: Zuber pegs back below-par Selecao|
|Warrington hold off Wakefield fightback, Tigers held despite Hitchcox heroics|
|Germany follow trend of poor starts for World Cup champions|
|Reed on the charge as U.S. Open race hots up|
|Milinkovic-Savic can play for any team in Europe, says Crespo|
|Southgate keen to unleash his bold new England|
|Konta fumes as Barty takes Nottingham title|
|Kante hails Pogba´s match-winning contribution|
|Germany struggle with generation gap|
|Neymar to make first competitive start since February in Brazil´s World Cup opener|
|Kane gunning for Ronaldo hat-trick heroics in England opener|
|Balotelli would fit in at Marseille - Raiola|
|Captain Ki happy to get tough on South Korea|
|Senegal call up Mbengue with Ciss ruled out|
|Mickelson celebrates at scene of Saturday meltdown|
|Germany 0 Mexico 1: Lozano stuns woeful reigning champions|
|Chandimal to face hearing after pleading not guilty to ball tampering|
|Griezmann ´must do more´, says Deschamps|
|Gasquet shows his class on grass to end Chardy´s chances|
|Courtois: Belgium outsiders not World Cup favourites|
|You can´t compare Ronaldo and Messi – Adrien Silva|
|Kiwis name seven uncapped players for England Test|
|Lorenzo tells critics: Remember MotoGP wins next time I struggle|
|Maaloul singles out ´future of English football´ Alli as main threat|
|Poland v Senegal: Nawalka waits on Glik|
|All Blacks draft in Riccitelli and Hemopo, Barrett not risked for third Test|
|Palermo to appeal play-off result after ´illegal game´|
|Once a year is not enough! - Alonso loved Le Mans bow|
|Colombia v Japan: Kawashima eager to right the wrongs of 2014|
|Russia v Egypt: Salah poised to derail hosts´ juggernaut|
|South Korea swapping kit numbers to confuse Sweden|
|Neuer, Ozil start for Germany in World Cup opener|
|Costa Rica and Serbia serve up plenty of the spectacular in sunny Samara|
|Alonso edges closer to ´Triple Crown´ with Le Mans glory|
|Costa Rica 0 Serbia 1: Kolarov stunner seals points|
|Belgium are better than Argentina – Gomez and Panama ignoring Iceland result|
|Messi, Ronaldo or Neymar would keep the goal - Evra defends Pogba|
|Two in a row for dominant Lorenzo in Barcelona|
|Maradona denies racism claim|
|Resilient Krunic breaks Tour duck|
|Federer wins Stuttgart Open on his return|
|Injured Vunipola to miss England´s series finale in South Africa|
|Ibrahimovic not involved in Sweden´s World Cup plans, insists Andersson|
|Sri Lanka captain Chandimal charged with ball tampering|
|Portugal will not underestimate Morocco, vows Adrien Silva|
|Messi is not Maradona, he does not win a World Cup alone - Crespo|
|Hourcade resigns after Pumas´ series defeat|
|Second place is worthless - Rivaldo admits pressure is on Neymar and Brazil|
|South Africa character made up for mistakes - Erasmus|
|No World Cup pressure for Serbia, insists Matic|
|England need to learn lessons now - Farrell|
|Russia´s Dzagoev to sit out Egypt clash|
|Bellamy celebrates new Storm deal with a win|
|Kane: England captaincy will not change my game|
|High-scoring U.S. Open ´a different kind of fun´, says Rose|
|Nigeria must return to the drawing board after Croatia defeat - Mikel|
|England head into Tunisia clash at full strength|
|Murray´s expectations ´very low´ on return|
|Rose: England are better prepared for the World Cup|
|Astros top Royals, push winning streak to 10|
|Spence knocks out Ocampo early, disappointed for crowd|