Mercedes has reportedly dismissed claims it will begin the 2015 season with its 'old' V6 engine of last year.

With the FIA agreeing to allow a development loophole under the existing 'freeze' rules, the sport's engine makers are currently contemplating how best to deploy their 32 upgrade 'tokens' throughout the 2015 season.

One rumour this week suggested Mercedes, having utterly dominated last year with its title-winning turbo V6, in fact planned to start the season with the 2014 unit in order to strategically upgrade to a 2015 specification over time.

But Italy's Omnicorse insists those reports are untrue, claiming the Brackley team is "assembling the car that will be taken to the Jerez test, and it will have the power unit configuration of 2015".

"The rumour that has spread in recent days about Mercedes doing the first four races with the 2014 power unit was denied," the report added.

Not only that, Omnicorse claims that Mercedes' 2015 engine will be significantly different this year, including a new Bosch injection system capable of turbo pressure to the regulations-maximum of 500 bar.

The report claimed Mercedes' 2014 turbo was limited to little more than half that figure.

(GMM)