A Monday report from GasBuddy showed a startling increase in the national average cost for a gallon of diesel.

According to a GasBuddy news release on May 9, the national average price of diesel has risen 22.6 cents in the last week and now stands at $5.52 per gallon.

AAA data shows a similar increase in costs, with today’s national average cost for a gallon of diesel at $5.540, compared to $5.321 a week ago, a 23 cent difference.

GasBuddy analyst Patrick De Haan pointed to reasons for the rising costs and looked at how American consumers will be affected.

“Gasoline and diesel prices alike saw strong upward momentum last week as oil prices continued to climb after the EU signaled its desire to sanction Russian oil. In addition, U.S. petroleum inventories saw yet another weekly decline as we near the start of summer driving season. Not only are diesel prices at a record high, they are at their largest differential to gasoline on record, surpassing the 98-cent difference in 2008 and currently standing at a $1.20 per gallon premium. While motorists filling with gasoline have seen a slight rise in prices, diesel’s surge will be a double whammy as diesel prices will soon be passed along to retail channels, further pushing up the cost of goods,” De Haan said.

Diesel supply issues have been reported on the East Coast, according to several news outlets.