WLNS.com reminded me today that an annual wallet nuisance is once again ready to return: summer gas prices. It's no myth...gas prices in Michigan do, indeed, rise during summer months. And, environmental science is the reason.

According to the WLNS report, in April, refineries begin producing what is known as summer-blend gasoline. I did a web search on the term, and came back with this article written by AAA. The long and short of it is, in the winter, to properly evaporate in colder temperatures, gasoline must be more volatile...quicker burn, less efficiency. Summer-blend has a lower volatility, but burns with more efficiency. Unfortunately, this has a higher cost to refine, and we pay the difference per gallon.

The good news in this, your mileage will be better with summer-blend. But, prices could reportedly be about forty cents more per gallon.