why did my car lose power while going up a hill? on 2007 Nissan Maxima

while driving at 60mph my car lost power going up a hill. pushing on the acelerator did not make it any faster. the temperature outside was around 22degrees ferenheit and i had warmed the car up for 15 minutes. the gas tank was a little less than a half a tank.

Asked by for the 2007 Nissan Maxima