Rising diesel prices have helped fuel inflation — and we’re about to see how much worse it could get

Thursday will provide more clues on the impact of record diesel prices ahead of the midterm elections. The consumer-price index came in hot Wednesday. The producer-price index, due Thursday, is likely to show the impact of rising diesel prices.

Wall Street wasn’t taking Wednesday’s hot consumer-price index lightly. And on Thursday, the producer-price index will be the last reading to help investors gauge the toll of surging diesel prices in the United States before the midterm elections. The August PPI data showed diesel prices jumped 24% month over month and 77% year over year, said Matt Miskin, co-chief investment strategist at Manulife John Hancock Investments.

That large an increase tells the economy and markets that there is a “serious problem that has developed.”