Citroen team principal Olivier Quesnel is adamant that this weekend's Rally Mexico will not offer a fair reflection of the performance of the DS3 WRC, despite the all-new French machines taking the top three fastest times at shakedown this morning.

Sebastien Ogier (ABOVE) was the fastest through the three-mile stage, two tenths of a second faster than Petter Solberg and 1.2sec up on Sebastien Loeb. Jari-Matti Latvala was the fastest Ford, 1.5sec down on Ogier.

"This event is very specific," said Quesnel. "It's the same for Ford as for us, we will not know exactly where we are until we go to the next round in Portugal."

Rally Mexico is run at high altitude, with the Ortega test peaking at close to 9,200ft. These conditions have a significant effect on the way the engine works, with the thinner air meaning less power from the 1.6-liter turbocharged engines.

Ford struggled in the high altitude events here in Mexico and Bulgaria last season, with Citroen taking a clean sweep of the podium in Leon 12 months ago.

In an effort to avoid a repeat of that result, M-Sport's engineers have worked closely with Ford's road car technicians on the dyno-cell unit at Ford's engine works in Dunton. The cell replicates high-altitude conditions, allowing the Fiesta RS WRC to be mapped to suit the roads on this second WRC round of the season, which starts this evening.