The weighted average price for all three grades surged by more than 38 cents a gallon to reach nearly $3.04 a gallon between 26 August and 9 September, said Trilby Lundberg, who publishes the semi-monthly Lundberg Survey of 7000 petrol stations around the US.
 
Self-serve regular averaged $3.01 a gallon nationwide, according to the survey. Midgrade was pegged at about $3.11 a gallon, while premium-grade was at nearly $3.21 a gallon.

"That's all thanks to Katrina," Lundberg said. Lundberg said the hurricane had cut 11% of the US petrol production capacity by decimating refineries and damaging pipelines.
 
Shutdowns

On Saturday, more than 120 Gulf of Mexico oil and gas platforms were still shut down and nearly 60% of the Gulf of Mexico's normal daily oil production remained blocked from the market because of evacuations due to Hurricane Katrina, the federal Minerals Management Service said.

Adjusted for inflation, the previous high weighted average for all three grades in the US was $1.38 a gallon in March 1981. That would be $3.03 a gallon in current dollars.
 
Lundberg said prices could drop sharply in the coming weeks as petrol imports flow in and demand eases with the traditional September drop-off, fewer drivers in storm-stricken areas and other consumers limiting trips to the pumps.