Winter temperatures running below the historic averages helped prop up crude oil in New York with prices holding at more than $98 per barrel Thursday.Light, sweet West Texas Intermediate crude on the New York Mercantile Exchange added 95 cents to hit $98.31 per barrel.Gasoline gained 0.71 cents to reach $2.668 a gallon.Home heating oil added 1.84 cents to hit $3.20 a gallon.Natural gas plunged 34 cents to reach $5.13 per million British thermal units. Natural gas prices have been fluctuating wildly with supplies low and demand high in some areas.The national average price of unleaded regular gasoline dropped to $3.275 per gallon from Wednesday's $3.277, the AAA Daily Fuel Gauge Report said.