Well, a 737-800 burns 12.5 gallons per minute. Southwest cancelled ~2500 flights, so 2500 flights x 90 minutes per flight x 12.5 gallons per minutes x 5 days of problems for them is about 14 million gallons of jet fuel. Average daily US diesel consumption is about 160 million gallons per day. (Diesel consumption is 4 times jet fuel consumption in the US.)
So no, you probably won't see much difference at the pump from that.
