By Alan Baldwin
LONDON (Reuters) - Formula One champions Mercedes say they are working hard to improve their cars' cooling systems for future races after struggling with overheating at the Austrian Grand Prix at the weekend.
Trackside engineering director Andrew Shovlin explained in a team post-race debrief on Wednesday that the 2019 car is so tightly packaged that the radiators are too small to provide sufficient cooling in extreme conditions.
"We’ve got a lot of projects looking at this particular issue with the cooling, how we can improve that," he said.
"And that work started well before the race weekend in Austria and there’s a lot of people here busy with that. And we will get on top of that and make progress."
Sunday's race at Spielberg ended dominant Mercedes's run of 10 wins in a row, and eight out of eight this season.
Finland's Valtteri Bottas finished a distant third on a hot afternoon, with championship leader Lewis Hamilton fifth in a race won by Red Bull's Max Verstappen ahead of Ferrari's Charles Leclerc.
"It all really goes down to the fundamental design of the car, where in the push for very, very tight packaging, we have ended up being undercooled overall," said Shovlin.
"Fundamentally the car doesn’t have big enough radiators.
"It’s meant that we are carrying this issue where in the very hot races we will be struggling... to keep the power unit cool enough that we don’t do any damage to it."
Shovlin explained that opening up the bodywork improved matters but the temperature in Austria was 35 degrees Celsius, at the upper end of what could be achieved by that simple expedient.
"We were on limit. When you get to that point you are really limited in your options. You can start to use lift and coast, which is where the drivers get towards the end of the straight and they back off the throttle," he said.
"They then brake a bit later and you have a period where the car is just coasting into the corner, the engine is not doing work and you can lose a fair bit of temperature like that."
The combination of having to lift and coast for some 400 meters of a 4.3-km lap, one of the shortest on the calendar, and turning down the engine meant performance was seriously compromised.
"It was (a tough afternoon). We had to manage lots of temperatures and we didn’t really run any of the good engine modes and (did) big amounts of lift and coast," Bottas said afterwards.
"So we couldn’t really race properly, attack or defend. It felt a bit like a survival game in the end to the flag."