California’s average retail price for all grades was $4.03 as of Sept. 30 — up 52 cents, or 15%, from Aug. 26.

That’s a much larger jump than what was seen nationally. U.S. pump prices were up 7.6 cents, or 3%, in the month to $2.74 a gallon.

That boost adds up to California drivers paying $1.29 more than the national norm — a 47% premium. It’s the biggest gap between state and national prices, according to agency data dating to 2000.