HOUSTON — With the Russian invasion of Ukraine grinding on, drivers will have to shell out a lot more to fill up their cars as the summer travel season begins this Memorial Day weekend.The price for regular gasoline in California has already risen to more than $6 a gallon, and it is virtually impossible to find gas for under $4 anywhere else. Nationwide, prices have risen by nearly 50 cents a gallon over the last month.The war in Ukraine is the most immediate cause for the jump in prices as global refiners, tanker companies and traders shun Russian exports, forcing up to three million barrels of oil a day off the market. Energy traders have also bid up oil prices in the expectation that Western governments will impose ev …
