Verstappen only just made it to the grid for the start of the Barcelona race before the pit exit closed, as his team waited for the temperature to rise to the minimum limit.
The fuel temperature limit is 10C below the ambient temperature displayed on the official FIA timing system two hours before the start of the race, or an hour before a practice session.
Teams track the temperature so they know how cool their fuel can be when it goes into the car two hours before the start, having calculated how much warmer it will get while sitting on the car and when the engine is run as part of the usual pre-race procedures.
They have to ensure that their fuel exceeds the limit when the cars leave the garage, with the FIA monitoring it live via the standard fuel flow meter.
Hitherto the temperature has been rounded to the nearest full degree. In Spain it had been in the low 34C range in the build-up to the race, so teams were expecting that to be the nominated figure, and thus fuel would have to be at 24C when the cars left the garage.
However on this occasion the FIA declared it at 35C, and teams were left scrambling to ensure that they got to the limit.
Red Bull and AlphaTauri were particularly affected, with Verstappen and Pierre Gasly leaving their garages just seconds before the pitlane closed.
Subsequently there has been a debate between teams and the FIA about the procedure, with some questioning if 35C was the true figure at the time it was declared.
In a Friday update to his Monaco event notes, race director Eduardo Freitas has indicated that a more accurate number will be used from now on, to avoid any confusion over rounding up.
Freitas wrote: “The official air temperature message, which is sent one hour before each practice session and two hours before the race, will now be displayed to one decimal place.”
Teams are also pushing for a longer term change to the procedure, which could involve the air temperature being declared earlier – three hours before the start for example – which would give them more time to make their temperature calculations before the fuel goes in the cars two hours before the start.
The fuel issue was first highlighted when the Aston Martins couldn’t go to the grid in Miami, as the team ensured the fuel heated up.
Gasly has made it clear how stressful it was to have to wait to be allowed out of the garage in Spain.
“At some point I could see the clock, and I was like, it would be great to go - we made it by about 20 seconds," he reflected when asked about the experience by Autosport.
“The thing is we kind of laughed about it before the race, about this [Aston Martin] fuel story that happened in Miami.
“And then we ended up in the same situation. I'm glad we managed to sort everything out.
"It's a small thing, it doesn't impact [the race] but it's just a small thing which we can avoid, and give an easier time to all the guys.”
