The cost of filling up your car is about to go higher.

Seasonal influences account for much of the expected increase that many analysts say will push gasoline (at a nationwide average of $2.70 yesterday) to at least $3 a gallon this spring. Rising oil prices also are a factor in higher gasoline prices.

Wholesale prices for the April gasoline contract on the New York Mercantile Exchange are about 10 to 12 cents higher than the March contract, which expired Friday. Much of the rise comes from refiners' switching to more expensive summer blends of gasoline designed to meet tougher pollution standards in effect between April and September. The higher prices should make their way to the pump over the next few weeks.

At $3 per gallon, a typical motorist using 50 gallons of gasoline would pay about $150 per month for fuel. That is about $15 a month more than current prices, according to OilPrice Information Service.

Prices have moved higher the past two weeks, approaching the 2010 high of $2.7583 per gallon set on Jan. 14. In the past week prices climbed 5.7 cents and are now 78.4 cents higher than year ago levels.