Williams chief technical officer Pat Symonds has suggested that the team may not use the upgraded Mercedes engine in 2015.
Lewis Hamilton raced to his seventh first-place podium last weekend while using the latest Mercedes engine, which is reportedly delivering an extra 40 horsepower.
However, Symonds is wary of the new power unit after Nico Rosberg's engine problems and insists that he has faith in the equipment Williams currently use.
When asked by Sky Sports News whether Williams would be upgrading their engine setup this year, Symonds answered: "To be honest I don't know. There is obviously some risk analysis to be undertaken to know whether to use the new power unit or not.
"I think we are incredibly satisfied with what we have got, we have got the best power unit in Formula 1 and Mercedes allow us to use it very, very aggressively. So we feel it is a very reliable and a very powerful unit and that is great for us.
"What it is really good to see, though, is that they are not resting on their laurels, they are the dominant power unit, yet they are still pushing really hard for 2016."
Despite the dominant victory by Hamilton, Williams drivers Felipe Massa and Valtteri Bottas finished in third and fourth respectively at the Italian Grand Prix.
