World Rally Championship leader Ott Tanak is confident there will not be a return of the cooling issues which have plagued Toyota's last two trips to Rally Mexico.
The Yaris WRC has struggled to acclimatise to the combination of the altitude and heat in Guanajuato, with two factory cars finishing sixth and seventh in 2017.
Last season, there was more speed, but only after all three of its cars retired with overheating and engine cooling-related issues.
Tanak says his victory at last September's Rally Turkey demonstrated the team was already on top of the issue.
"I believe everything will be good," Tanak told Autosport.
"I'm confident - we saw the first good step [with the car] was coming before Turkey.
"Since Turkey we have done another step.
"OK, the altitude makes things are a bit worse than in Turkey, but if the engineers are confident then we shouldn't worry."
In an effort to replicate the gravel-strewn roads of Mexico, Toyota Gazoo Racing found a number of different roads for Tanak to drive during his pre-event test in Spain.
Despite Tanak running first on the road, Sebastien Ogier demonstrated winning from the front is possible when he did so in 2013 and 2015.
"I believe it's possible to win every rally," Tanak said.
"But everything needs to be in your favour.
"Being first [on the road on Friday] is definitely not the easiest position to win.
"The main aim is to score points, but if there is an opportunity then I intend to use it."
Both Citroen's Sebastien Ogier and Toyota's Kris Meeke will get their first competitive running on gravel in their respective new cars.
Five-time champion Ogier swaps a Ford Fiesta for a Citroen C3 this year, but followed his season-opening win on the Monte Carlo Rally with a crash in Sweden.
"After a tough Rally Sweden, where we weren't able to express ourselves, I can't wait to get started and realise our full potential," said Ogier.
"We had two good days of pre-event testing, on roads that were fairly representative of the kind of stages we'll have to tackle this weekend."
Meeke hinted he could be closer to the sharp end after a pair of sixth places to start the season in his Yaris WRC.
"I wanted to get through the first two rallies with points on the board: Monte Carlo and Sweden were events with very complicated conditions where it would have been easy to make a mistake," said Meeke.
"I've done that and now Mexico is usually a lot more consistent and I'm looking forward to it."
Meeke's fellow Briton Elfyn Evans has said a "radical change" to his Fiesta "sets us [M-Sport] up nicely for Mexico".
The M-Sport team was competitive in Sweden setting top times, but both Evans and Teemu Sunninen crashed.
"I take a lot of confidence from that event into this week and I want to carry on where we left off," said Evans.
Nine-time WRC champion Sebastien Loeb drops to the sidelines in Mexico after starting the first two rounds, as Hyundai team-mate Dani Sordo takes over in the i20 Coupe WRC they share this year.
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