Does it affect my car’s performance?
Cars using summer-blend gasoline spew fewer harmful emissions and get slightly better fuel economy than those using winter-blend gas during the summer months.
The difference between conventional summer- and winter-blend gasoline has to do with the Reid Vapor Pressure of the fuel. RVP relates to the volatility of a gasoline. The more volatile a gasoline, the more likely it will evaporate as the temperatures rises; evaporated gasoline contributes to unhealthy ozone and smog levels. Summer gasoline has a low RVP and is less likely to evaporate when compared to the high RVP winter grade. The Environmental Protection Agency says conventional summer-blend gasoline contains 1.7 percent more energy than winter-blend gas, which contributes to the summer blend’s slightly better gas mileage.
The Energy Information Administration says the switch between the two fuels happens twice a year, once in the fall (winter blend) and again in the spring (summer blend). Summer-blend gasoline is typically more expensive to produce than the winter blend, and it won’t affect vehicle performance or the durability of the engine and fuel system, according to the EPA.
In many large cities as well as California and New England, the EPA requires the use of reformulated summer- and winter-blend gasolines. These RFGs contain oxygenates that lower RVP and other toxic chemicals even further than conventional gasoline.
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So why can't they make summer-blend all year long?
J summer-blend gas doesn’t perform as well in cold temperatures. The summer gas can make cold engine start ups difficult.
The article states you get slightly better gas mileage on the summer blend. I'm wondering what they consider slight. My first vehicle went from 18mpg in the winter to 24mpg in the summer, and my second vehicle went from 26mpg in the winter to 33mpg in the summer. I consider that a considerable difference.
Who cares when these blends of gasoline start, I want to know how much it cost the oil companies per gallon of gas to make it into a summer blend. I can't believe it runs .50 to $1.00 a gallon to make it a summer blend!
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I have read winter blend gasoline begins around Sept 15. do you know when summer blended gas begins?