The Germans, World Cup winners in 2014, kick off their title defence at Moscow's Luzhniki Stadium and Loew said his players had nothing else on their mind other than winning their opener.
"The (2014) title plays no role. The tension we have is a positive tension and you can feel it rising. What you won in the past does not matter," he said.
"Before the first match everyone has this positive tension. You want it to start, to prove yourself, to take a good step in this tournament and it does not matter what you have won or not."
Loew has been in charge since 2006 and his team has won every tournament opener at Euros and World Cups under him, a run they want to extend against the Mexicans.
He said that setbacks during their preparation for Russia, such as a loss to Austria and a scrappy win against Saudi Arabia in their final warm-up games, never shifted the team's focus.
"It is correct that we have won a lot of opening matches. We accept that in our preparation things may go wrong at some point. What we focus on is the first tournament game and in the first games we have always shown our good performance," Loew said.
"It has to do with the self confidence of the players. I hope we can succeed tomorrow against a very tough opponent who plays well in almost every aspect of their game."
The Germans have won all three tournament encounters against the Mexicans, including their 4-1 demolition at last year's Confederations Cup. German FA records state that in 11 matches Mexico have managed just one victory.
But midfielder Julian Draxler, who captained a largely second-string Germany to the Confederations Cup title, warned that Sunday's encounter would be a completely different affair.
"Our team has changed a lot from the Confederations Cup," Draxler said. "We should not read too much into that win last year. It will be a completely different game.
"Mexico is collectively strong, play pressing and can put the opponent under pressure."
Germany also play South Korea and Sweden in their group.
(Reporting by Karolos Grohmann; Editing by Christian Radnedge)
