Vettel leads the drivers' title standings by 60 points after seven races and his Red Bull team have been dominant in qualifying, claiming pole position at every qualifying session so far.
While neither Vettel nor Webber have shown the same pace on a Sunday as they have during the Saturday, with a strong starting position, both drivers have usually been able to maximise their performance.
Analysts suspect the team have been implementing an "extreme engine map" during qualifying, where ultimately one quick lap is required, before then easing off and using a more reasonable set-up for the following day's race.
An extreme engine map could produce more exhaust or burn more fuel, both of which would make the car quicker.
Going into this weekend's European Grand Prix, the decision of the sport's governing body effectively prevents the 12 race teams from altering their engine maps between qualifying and racing, meaning Red Bull's pace in qualifying should, to an extent, appear similar the next day.
Vettel, however, said "there are no secrets" in his team and that he does not expect the decision to have an effect on his challenge for a second successive title.
"I am not worried," he said. "It is something that everybody was playing around with, especially this year.
"It makes a difference to everyone, but I don't think it makes a bigger difference to us than others. It's the same for all the teams.
"Usually, I have been quite good at communicating with the team, and I don't think they are hiding anything from me.
"There are no secrets and, from what I know, there is nothing special going on between the Saturday and Sunday."
Webber conceded the new ruling "won't make the car any faster" but added it is "unlikely to change the championship".
"They will be the same for everybody. We need to adapt again and get used to it, but our team are used to adapting to a change in the regulations," he said.
"I don't think it will turn the field upside-down, but everyone will be in reasonable shape. We are quick."
Not everybody is so convinced, however.
Button became only the second driver to beat Vettel this season after passing the German on the final lap at the Canadian Grand Prix in Montreal earlier this month, and he is hoping the new rule will allow him to keep applying the pressure on Vettel and his team.
"We are going to be hurt by the engine mapping rule," Button said.
"It will make a big difference to us in qualifying, but it will make a bigger difference to Red Bull, because if you look at their pace in qualifying against their race pace it is very different, so I am hoping they are going to have more issues than we will.
"I still think they will be quicker than us, but hopefully we can get closer and really fight them in the race."
Button expects tomorrow's qualifying to be a more tense affair with the teams at the front weakened and the teams in the middle order posting times closer to the championship challengers.
He maintains, however, that his focus remains on Vettel, Webber and the Red Bulls, and said his win in Canada is proof that "if we put them under pressure, maybe they will make mistakes".
Doing so is a necessity, he said, because: "If we don't do that they are invincible."